The integrated service (IntServ) model is a multiple-service model that can accommodate diverse QoS requirements. This service model provides the most granularly differentiated QoS by identifying and guaranteeing definite QoS for each data flow.

In the IntServ model, an application must request service from the network before it sends data. IntServ signals the service request with the RSVP. All nodes receiving the request reserve resources as requested and maintain state information for the application flow. For more information about RSVP, see MPLS Configuration Guide.

The IntServ model demands high storage and processing capabilities because it requires all nodes along the transmission path to maintain resource state information for each flow. This model is suitable for small-sized or edge networks. However, it is not suitable for large-sized networks, for example, the core layer of the Internet, where billions of flows are present.

DiffServ model

The differentiated service (DiffServ) model is a multiple-service model that can meet diverse QoS requirements. It is easy to implement and extend. DiffServ does not signal the network to reserve resources before sending data, as IntServ does.

QoS techniques in a network

The QoS techniques include the following features:

· Traffic classification.

· Traffic policing.

· Traffic shaping.

· Rate limit.

· Congestion management.

· Congestion avoidance.

The following section briefly introduces these QoS techniques.

All QoS techniques in this document are based on the DiffServ model.

Figure 1 Position of the QoS techniques in a network

As shown in Figure 1, traffic classification, traffic shaping, traffic policing, congestion management, and congestion avoidance mainly implement the following functions:

· Traffic classification—Uses match criteria to assign packets with the same characteristics to a traffic class. Based on traffic classes, you can provide differentiated services.

· Traffic policing—Polices flows and imposes penalties to prevent aggressive use of network resources. You can apply traffic policing to both incoming and outgoing traffic of a port.

· Traffic shaping—Adapts the output rate of traffic to the network resources available on the downstream device to eliminate packet drops. Traffic shaping usually applies to the outgoing traffic of a port.

· Congestion management—Provides a resource scheduling policy to determine the packet forwarding sequence when congestion occurs. Congestion management usually applies to the outgoing traffic of a port.

· Congestion avoidance—Monitors the network resource usage. It is usually applied to the outgoing traffic of a port. When congestion worsens, congestion avoidance reduces the queue length by dropping packets.

QoS processing flow in a device

Figure 2 briefly describes how the QoS module processes traffic.

1. Traffic classifier identifies and classifies traffic for subsequent QoS actions.

2. The QoS module takes various QoS actions on classified traffic as configured, depending on the traffic processing phase and network status. For example, you can configure the QoS module to perform the following operations:

¡ Traffic policing for incoming traffic.

¡ Traffic shaping for outgoing traffic.

¡ Congestion avoidance before congestion occurs.

¡ Congestion management when congestion occurs.

Figure 2 QoS processing flow

QoS configuration approaches

You can configure QoS by using the MQC approach or non-MQC approach.

In the modular QoS configuration (MQC) approach, you configure QoS service parameters by using QoS policies. A QoS policy defines QoS actions to take on different classes of traffic and can be applied to an object (such as an interface) to control traffic.

In the non-MQC approach, you configure QoS service parameters without using a QoS policy. For example, you can use the rate limit feature to set a rate limit on an interface without using a QoS policy.

Some features support both approaches, but some support only one.

Configuring a QoS policy

About QoS policies

A QoS policy has the following components:

· Traffic class—Defines criteria to match packets.

· Traffic behavior—Defines QoS actions to take on matching packets.

By associating a traffic class with a traffic behavior, a QoS policy can perform the QoS actions on matching packets.

A QoS policy can have multiple class-behavior associations.

QoS policy tasks at a glance

To configure a QoS policy, perform the following tasks:

1. Defining a traffic class

2. Defining a traffic behavior

3. Defining a QoS policy

4. Applying the QoS policy

¡ Applying the QoS policy to an interface

¡ Applying the QoS policy to VLANs

¡ Applying the QoS policy globally

¡ Applying the QoS policy to a control plane

Defining a traffic class

1. Enter system view.

system-view

2. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

3. (Optional.) Configure a description for the traffic class.

description text

By default, no description is configured.

4. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured.

For more information, see the if-match command in ACL and QoS Command Reference.

Defining a traffic behavior

1. Enter system view.

system-view

2. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

3. Configure an action in the traffic behavior.

By default, no action is configured for a traffic behavior.

For more information about configuring an action, see the subsequent chapters for traffic policing, traffic filtering, priority marking, class-based accounting, and so on.

Defining a QoS policy

Restrictions and guidelines

The device supports the following QoS policy types:

· Accounting—Can contain only class-based accounting actions.

· Marking—Can contain only marking actions.

· Generic—Can contain all actions.

If you do not specify the accounting or remarking keyword when creating a QoS policy, a generic QoS policy is created.

QoS policies of different types cannot have the same policy name.

Procedure

1. Enter system view.

system-view

2. Create a QoS policy and enter QoS policy view.

qos [ accounting | remarking ] policy policy-name

3. Associate a traffic class with a traffic behavior to create a class-behavior association in the QoS policy.

classifier classifier-name behavior behavior-name [ mode { dcbx | qppb-manipulation } |insert-before before-classifier-name ] *

By default, a traffic class is not associated with a traffic behavior.

Repeat this step to create more class-behavior associations.

Table 1 Parameter description

Parameter	Description
accounting	Represents an accounting-type QoS policy.
remarking	Represents a marking-type QoS policy.
dcbx	Specifies that a class-behavior association applies only to DCBX. For more information about DCBX, see Layer 2—LAN Switching Configuration Guide.
qppb-manipulation	Specifies that a class-behavior association applies only to matching the apply qos-local-id command configuration in a BGP routing policy. For more information, see Layer 3—IP Routing Configuration Guide.

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Applying the QoS policy

Application destinations

You can apply a QoS policy to the following destinations:

· Interface—The QoS policy can be applied to the traffic sent or received on the interface.

· Globally—The QoS policy can be applied to the traffic sent or received on all ports.

· VLAN—The QoS policy can be applied to the traffic sent or received on all ports in the VLAN.

· Control plane—The QoS policy can be applied to the traffic received on the control plane.

Restrictions and guidelines for applying a QoS policy

You can modify traffic classes, traffic behaviors, and class-behavior associations in a QoS policy even after it is applied. If a traffic class uses an ACL for traffic classification, you can delete or modify the ACL.

When a QoS policy containing a CAR action is applied to the inbound direction of multiple interfaces, the actual rate limit that takes effect depends on the interface groups of these interfaces. By default, the actual rate limit that takes effect is the CIR plus the PIR specified in the CAR action multiplied by the number of involved interface groups. Interfaces on different cards belong to different interface groups. To identify interface group information, execute the debug port mapping command for the specified slot in probe view. Interfaces with the same Unit value belong to the same interface group.

When a QoS policy containing a CAR action is applied to the outbound direction of multiple interfaces, the actual rate limit that takes effect depends on the locations of these interfaces. By default, the actual rate limit that takes effect is the CIR plus the PIR specified in the CAR action multiplied by the number of cards where the interfaces reside.

Applying the QoS policy to an interface

Restrictions and guidelines

A QoS policy can be applied to multiple interfaces.

Only one QoS policy of the same type can be applied to one direction (inbound or outbound) of an interface.

The QoS policy applied to the outgoing traffic on an interface does not regulate local packets. Local packets refer to critical protocol packets sent by the local system for operation maintenance.

You can configure the sharing mode for QoS and ACL resources only if you apply a QoS policy to an interface.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Apply the QoS policy to the interface.

qos apply [ accounting | remarking ] policy policy-name { inbound [ extension ] | outbound } [ share-mode ]

By default, no QoS policy is applied to an interface.

Applying the QoS policy to VLANs

About this task

You can apply a QoS policy to VLANs to regulate the traffic on all ports of the VLANs.

Restrictions and guidelines

QoS policies cannot be applied to dynamic VLANs.

When you apply a QoS policy to VLANs, the QoS policy is applied to the specified VLANs on all interface cards. If the hardware resources of an interface card are insufficient, applying a QoS policy to VLANs might fail on the interface card. The system does not automatically roll back the QoS policy configuration already applied to other interface cards. To ensure consistency, use the undo qos vlan-policy command to manually remove the QoS policy configuration applied to them.

Procedure

1. Enter system view.

system-view

2. Apply the QoS policy to VLANs.

qos vlan-policy policy-name vlan vlan-id-list { inbound [ extension ] | outbound }

By default, no QoS policy is applied to a VLAN.

Applying the QoS policy globally

About this task

You can apply a QoS policy globally to the inbound or outbound direction of all ports.

Restrictions and guidelines

· A maximum of three QoS policies can be applied to one direction globally: one accounting-type, one marking-type, and one generic.

· If the hardware resources of an interface card are insufficient, applying a QoS policy globally might fail on the interface card. The system does not automatically roll back the QoS policy configuration already applied to other interface cards. To ensure consistency, you must use the undo qos apply policy global command to manually remove the QoS policy configuration applied to them.

Procedure

1. Enter system view.

system-view

2. Apply the QoS policy globally.

qos apply [ accounting | remarking ] policy policy-name global { inbound [ extension ] | outbound }

By default, no QoS policy is applied globally.

Applying the QoS policy to a control plane

About this task

A device provides the user plane and the control plane.

· User plane—The units at the user plane are responsible for receiving, transmitting, and switching (forwarding) packets, such as various dedicated forwarding chips. They deliver super processing speeds and throughput.

· Control plane—The units at the control plane are processing units running most routing and switching protocols. They are responsible for protocol packet resolution and calculation, such as CPUs. Compared with user plane units, the control plane units allow for great packet processing flexibility but have lower throughput.

When the user plane receives packets that it cannot recognize or process, it transmits them to the control plane. If the transmission rate exceeds the processing capability of the control plane, the control plane will be busy handling undesired packets. As a result, the control plane will fail to handle legitimate packets correctly or timely. As a result, protocol performance is affected.

To address this problem, apply a QoS policy to the control plane to take QoS actions, such as traffic filtering or traffic policing, on inbound traffic. This ensures that the control plane can correctly receive, transmit, and process packets.

A predefined control plane QoS policy uses the protocol type or protocol group type to identify the type of packets sent to the control plane. You can use protocol types or protocol group types in if-match control-plane commands in traffic class view for traffic classification. Then you can reconfigure traffic behaviors for these traffic classes as required. You can use the display qos policy control-plane pre-defined command to display predefined control plane QoS policies.

Procedure

1. Enter system view.

system-view

2. Enter control plane view.

control-plane slot slot-number

3. Apply the QoS policy to the control plane.

qos apply policy policy-name inbound

By default, no QoS policy is applied to a control plane.

Display and maintenance commands for QoS policies

Execute display commands in any view and reset commands in user view.

Task	Command
Display traffic class configuration.	display traffic classifier user-defined [ classifier-name ] [ slot slot-number ]
Display traffic behavior configuration.	display traffic behavior user-defined [ behavior-name ] [ slot slot-number ]
Display QoS and ACL resource usage.	display qos-acl resource [ slot slot-number ]
Display QoS policy configuration.	display qos policy user-defined [ accounting \| remarking ] [ policy-name [ classifier classifier-name ] ] [ slot slot-number ]
Display information about QoS policies applied to interfaces.	display qos [ accounting \| remarking ] policy interface [ interface-type interface-number ] [ slot slot-number \| all ] [ inbound \| outbound ]
Display information about QoS policies applied to VLANs.	display qos vlan-policy { name policy-name \| vlan vlan-id } [ slot slot-number ] [ inbound \| outbound ]
Display information about QoS policies applied globally.	display qos [ accounting \| remarking ] policy global [ slot slot-number ] [ inbound \| outbound ]
Display information about QoS policies applied to a control plane.	display qos policy control-plane slot slot-number
Display information about the predefined QoS policy applied to the control plane.	display qos policy control-plane pre-defined [ slot slot-number ]
Clear the statistics of the QoS policy applied in a certain direction of a VLAN.	reset qos vlan-policy [ vlan vlan-id ] [ inbound \| outbound ]
Clear the statistics for a QoS policy applied globally.	reset qos [ accounting \| remarking ] policy global [ inbound \| outbound ]
Clear the statistics for the QoS policy applied to a control plane.	reset qos policy control-plane slot slot-number

Configuring priority mapping

About priority mapping

When a packet arrives, a device assigns a set of QoS priority parameters to the packet based on either of the following:

· A priority field carried in the packet.

· The port priority of the incoming port.

This process is called priority mapping. During this process, the device can modify the priority of the packet according to the priority mapping rules. The set of QoS priority parameters decides the scheduling priority and forwarding priority of the packet.

Priority mapping is implemented with priority maps and involves the following priorities:

· 802.1p priority.

· DSCP.

· EXP.

· IP precedence.

· Local precedence.

· Drop priority.

About priorities

Priorities include the following types: priorities carried in packets, and priorities locally assigned for scheduling only.

Packet-carried priorities include 802.1p priority, DSCP precedence, IP precedence, and EXP. These priorities have global significance and affect the forwarding priority of packets across the network. For more information about these priorities, see "Appendixes."

Locally assigned priorities only have local significance. They are assigned by the device only for scheduling. These priorities include the local precedence, drop priority, and user priority, as follows:

· Local precedence—Used for queuing. A local precedence value corresponds to an output queue. A packet with higher local precedence is assigned to a higher priority output queue to be preferentially scheduled.

· Drop priority—Used for making packet drop decisions. Packets with the highest drop priority are dropped preferentially.

· User priority—Precedence that the device automatically extracts from a priority field of the packet according to its forwarding path. It is a parameter for determining the scheduling priority and forwarding priority of the packet. The user priority represents the following items:

¡ The 802.1p priority for Layer 2 packets.

¡ The IP precedence for Layer 3 packets.

¡ The EXP for MPLS packets.

Priority maps

The device provides various types of priority maps. By looking through a priority map, the device decides which priority value to assign to a packet for subsequent packet processing.

The default priority maps (as shown in Appendix B Default priority maps) are available for priority mapping. They are adequate in most cases. If a default priority map cannot meet your requirements, you can modify the priority map as required.

Priority mapping configuration methods

You can configure priority mapping by using any of the following methods:

· Configuring priority trust mode—In this method, you can configure a port to look up a trusted priority type (802.1p, for example) in incoming packets in the priority maps. Then, the system maps the trusted priority to the target priority types and values.

· Changing port priority—If no packet priority is trusted, the port priority of the incoming port is used. By changing the port priority of a port, you change the priority of the incoming packets on the port.

· Configuring a QoS policy containing the priority mapping (called primap) action with the primap command.

Priority mapping process

On receiving an Ethernet packet on a port, the device marks the scheduling priorities (local precedence and drop precedence) for the Ethernet packet. This procedure is done according to the priority trust mode of the receiving port and the 802.1Q tagging status of the packet, as shown in Figure 3.

Figure 3 Priority mapping process for an Ethernet packet

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The device marks a received MPLS packet with a scheduling priority based on the priority trust mode and the packet EXP value, as shown in Figure 4.

Figure 4 Priority mapping process for an MPLS packet

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For information about priority marking, see "Configuring priority marking."

Priority mapping tasks at a glance

To configure priority mapping, perform the following tasks:

1. (Optional.) Configuring a priority map

2. configure a priority mapping method:

¡ Configuring a port to trust packet priority for priority mapping

¡ Changing the port priority of an interface

Configuring a priority map

About this task

Table 2 shows the priority maps provided by the device.

Table 2 Priority maps

Priority map	Description
dot1p-dp	802.1p-drop priority map.
dot1p-dscp	802.1p-DSCP priority map.
dot1p-lp	802.1p-local priority map.
dscp-dot1p	DSCP-802.1p priority map.
dscp-dp	DSCP-drop priority map.
dscp-dscp	DSCP-DSCP priority map.
dscp-exp	DSCP-EXP priority map.
exp-dot1p	EXP-802.1p priority map.
exp-dscp	EXP-DSCP priority map.

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Procedure

1. Enter system view.

system-view

2. (Optional.) Modify the 802.1p priority of outgoing packets as the local precedence value.

dot1p-trust-tc

By default, the 802.1p priority of an outgoing packet is not modified.

For an 802.1p priority marking action in a QoS policy to take effect, this command must be configured. For information about configuring an 802.1p priority marking action, see "Configuring priority marking."

3. Enter priority map view.

qos map-table { dot1p-dp | dot1p-dscp | dot1p-lp | dscp-dot1p| dscp-dp | dscp-dscp | dscp-exp | exp-dot1p | exp-dscp }

4. Configure mappings for the priority map.

import import-value-list export export-value

By default, the default priority maps are used. For more information, see "Appendix B Default priority maps."

If you execute this command multiple times, the most recent configuration takes effect.

Configuring a port to trust packet priority for priority mapping

About this task

You can configure the device to trust a particular priority field carried in packets for priority mapping on ports or globally.

When you configure the trusted packet priority type on an interface, use the following available keywords:

· dot1p—Uses the 802.1p priority of received packets for mapping.

· dscp—Uses the DSCP precedence of received IP packets for mapping.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Configure the trusted packet priority type.

qos trust { dot1p | dscp }

By default, an interface does not trust any packet priority.

Changing the port priority of an interface

About this task

If an interface does not trust any packet priority, the device uses its port priority to look for priority parameters for the incoming packets. By changing port priority, you can prioritize traffic received on different interfaces.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Set the port priority of the interface.

qos priority [ dscp ] priority-value

By default, The port priority is 0, and the DSCP value of packets is not modified.

Display and maintenance commands for priority mapping

Execute display commands in any view.

Task	Command
Display priority map configuration.	display qos map-table [ dot1p-dp \| dot1p-dscp \| dot1p-lp \| dscp-dot1p\| dscp-dp \| dscp-dscp \| dscp-exp \| exp-dot1p \| exp-dscp ]
Display the trusted packet priority type on a port.	display qos trust interface [ interface-type interface-number ]

Priority mapping configuration examples

Example: Configuring a priority trust mode

Network configuration

As shown in Figure 5:

· The 802.1p priority of traffic from Device A to Device C is 3.

· The 802.1p priority of traffic from Device B to Device C is 1.

Configure Device C to preferentially process packets from Device A to the server when HundredGigE 1/0/3 of Device C is congested.

Figure 5 Network diagram

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Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

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(Method 1) Configure Device C to trust packet priority

# Configure HundredGigE 1/0/1 and HundredGigE 1/0/2 to trust 802.1p priority for priority mapping.

<DeviceC> system-view

[DeviceC] interface hundredgige 1/0/1

[DeviceC-HundredGigE1/0/1] qos trust dot1p

[DeviceC-HundredGigE1/0/1] quit

[DeviceC] interface hundredgige 1/0/2

[DeviceC-HundredGigE1/0/2] qos trust dot1p

[DeviceC-HundredGigE1/0/2] quit

(Method 2) Configure Device C to trust port priority

# Assign port priority to HundredGigE 1/0/1 and HundredGigE 1/0/2. Make sure the following requirements are met:

· The priority of HundredGigE 1/0/1 is higher than that of HundredGigE 1/0/2.

· No trusted packet priority type is configured on HundredGigE 1/0/1 or HundredGigE 1/0/2.

<DeviceC> system-view

[DeviceC] interface hundredgige 1/0/1

[DeviceC-HundredGigE1/0/1] qos priority 3

[DeviceC-HundredGigE1/0/1] quit

[DeviceC] interface hundredgige 1/0/2

[DeviceC-HundredGigE1/0/2] qos priority 1

[DeviceC-HundredGigE1/0/2] quit

Configuring traffic policing, GTS, and rate limit

About traffic policing, GTS, and rate limit

Traffic limit helps assign network resources (including bandwidth) and increase network performance. For example, you can configure a flow to use only the resources committed to it in a certain time range. This avoids network congestion caused by burst traffic.

Traffic policing, Generic Traffic Shaping (GTS), and rate limit control the traffic rate and resource usage according to traffic specifications. You can use token buckets for evaluating traffic specifications.

Traffic evaluation and token buckets

Token bucket features

A token bucket is analogous to a container that holds a certain number of tokens. Each token represents a certain forwarding capacity. The system puts tokens into the bucket at a constant rate. When the token bucket is full, the extra tokens cause the token bucket to overflow.

Evaluating traffic with the token bucket

A token bucket mechanism evaluates traffic by looking at the number of tokens in the bucket. If the number of tokens in the bucket is enough for forwarding the packets:

· The traffic conforms to the specification (called conforming traffic).

· The corresponding tokens are taken away from the bucket.

Otherwise, the traffic does not conform to the specification (called excess traffic).

A token bucket has the following configurable parameters:

· Mean rate at which tokens are put into the bucket, which is the permitted average rate of traffic. It is usually set to the committed information rate (CIR).

· Burst size or the capacity of the token bucket. It is the maximum traffic size permitted in each burst. It is usually set to the committed burst size (CBS). The set burst size must be greater than the maximum packet size.

Each arriving packet is evaluated.

Complicated evaluation

You can set two token buckets, bucket C and bucket E, to evaluate traffic in a more complicated environment and achieve more policing flexibility. The following are main mechanisms used for complicated evaluation:

· Single rate two color—Uses one token bucket and the following parameters:

¡ CIR—Rate at which tokens are put into bucket C. It sets the average packet transmission or forwarding rate allowed by bucket C.

¡ CBS—Size of bucket C, which specifies the transient burst of traffic that bucket C can forward.

When a packet arrives, the following rules apply:

¡ If bucket C has enough tokens to forward the packet, the packet is colored green.

¡ Otherwise, the packet is colored red.

· Single rate three color—Uses two token buckets and the following parameters:

¡ CIR—Rate at which tokens are put into bucket C. It sets the average packet transmission or forwarding rate allowed by bucket C.

¡ CBS—Size of bucket C, which specifies the transient burst of traffic that bucket C can forward.

¡ EBS—Size of bucket E minus size of bucket C, which specifies the transient burst of traffic that bucket E can forward. The EBS cannot be 0. The size of E bucket is the sum of the CBS and EBS.

When a packet arrives, the following rules apply:

¡ If bucket C has enough tokens, the packet is colored green.

¡ If bucket C does not have enough tokens but bucket E has enough tokens, the packet is colored yellow.

¡ If neither bucket C nor bucket E has sufficient tokens, the packet is colored red.

· Two rate three color—Uses two token buckets and the following parameters:

¡ CIR—Rate at which tokens are put into bucket C. It sets the average packet transmission or forwarding rate allowed by bucket C.

¡ CBS—Size of bucket C, which specifies the transient burst of traffic that bucket C can forward.

¡ PIR—Rate at which tokens are put into bucket E, which specifies the average packet transmission or forwarding rate allowed by bucket E.

¡ EBS—Size of bucket E, which specifies the transient burst of traffic that bucket E can forward.

When a packet arrives, the following rules apply:

¡ If bucket C has enough tokens, the packet is colored green.

¡ If bucket C does not have enough tokens but bucket E has enough tokens, the packet is colored yellow.

¡ If neither bucket C nor bucket E has sufficient tokens, the packet is colored red.

Traffic policing

A typical application of traffic policing is to supervise the specification of traffic entering a network and limit it within a reasonable range. Another application is to "discipline" the extra traffic to prevent aggressive use of network resources by an application. For example, you can limit bandwidth for HTTP packets to less than 50% of the total. If the traffic of a session exceeds the limit, traffic policing can drop the packets. Figure 6 shows an example of policing outbound traffic on an interface.

Figure 6 Traffic policing

Traffic policing can classify the policed traffic and take predefined policing actions on each packet depending on the evaluation result:

· Forwarding the packet.

· Dropping the packet.

· Forwarding the packet with its precedence re-marked.

· Delivering the packet to next-level traffic policing with its precedence re-marked.

GTS

GTS limits the traffic rate by buffering exceeding traffic. You can use GTS to adapt the traffic output rate on a device to the input traffic rate of its connected device to avoid packet loss.

The differences between traffic policing and GTS are as follows:

· Packets to be dropped with traffic policing are retained in a buffer or queue with GTS, as shown in Figure 7. When enough tokens are in the token bucket, the buffered packets are sent at an even rate.

· GTS can result in additional delay and traffic policing does not.

Figure 7 GTS

For example, in Figure 8, Device B performs traffic policing on packets from Device A and drops packets exceeding the limit. To avoid packet loss, you can perform GTS on the outgoing interface of Device A so that packets exceeding the limit are cached in Device A. Once resources are released, GTS takes out the cached packets and sends them out.

Figure 8 GTS application

Rate limit

The rate limit of an interface specifies the maximum rate for forwarding packets (excluding critical packets).

Rate limit also uses token buckets for traffic control. When rate limit is configured on an interface, a token bucket handles all packets to be sent through the interface for rate limiting. If enough tokens are in the token bucket, packets can be forwarded. Otherwise, packets are put into QoS queues for congestion management. In this way, the traffic passing the interface is controlled.

Figure 9 Rate limit implementation

The token bucket mechanism limits traffic rate when accommodating bursts. It allows bursty traffic to be transmitted if enough tokens are available. If tokens are scarce, packets cannot be transmitted until efficient tokens are generated in the token bucket. It restricts the traffic rate to the rate for generating tokens.

Rate limit controls the total rate of all packets on an interface or PW. It is easier to use than traffic policing in controlling the total traffic rate.

Configuring traffic policing

Configuring traffic policing by using the MQC approach

Restrictions and guidelines

A traffic policing action takes effect only when a QoS policy is applied to the inbound direction of an interface.

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured.

For more information about the if-match command, see ACL and QoS Command Reference.

c. Return to system view.

quit

3. Define a traffic behavior.

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Configure a traffic policing action.

¡ car cir committed-information-rate [ cbs committed-burst-size [ ebs excess-burst-size ] ] [ green action | red action | yellow action ] *

car cir committed-information-rate [ cbs committed-burst-size ] pir peak-information-rate [ ebs excess-burst-size ] [ green action | red action | yellow action ] *

By default, no traffic policing action is configured.

c. Return to system view.

quit

4. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos policy policy-name

b. Associate the traffic class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

5. Apply the QoS policy.

For more information, see "Applying the QoS policy."

By default, no QoS policy is applied.

Configuring traffic policing for all traffic

Restrictions and guidelines

This feature is supported only in F3607P02 and later.

For percentage-based traffic policing to take effect on the following interfaces, you must first use the bandwidth command to set the expected bandwidth of the interface:

· Layer 2 aggregate interface.

· Layer 3 aggregate interface.

· Layer 3 aggregate subinterface.

For more information about the bandwidth command, see Ethernet interface commands in Layer 2—LAN Switching Command Reference.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Configure a CAR policy for all traffic on the interface.

¡ In absolute value:

qos car inbound any cir committed-information-rate [ cbs committed-burst-size [ ebs excess-burst-size ] ]

qos car inbound any cir committed-information-rate [ cbs committed-burst-size ] pir peak-information-rate [ ebs excess-burst-size ]

¡ In percentage:

qos car inbound any percent cir cir-percent [ cbs cbs-time [ ebs ebs-time ] ]

qos car inbound any percent cir cir-percent [ cbs cbs-time ] pir pir-percent [ ebs ebs-time ]

By default, no CAR policy is configured on an interface.

Configuring GTS

Restrictions and guidelines

The GTS configuration takes effect only on outgoing traffic.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Configure GTS for a queue.

qos gts queue queue-id cir committed-information-rate [ cbs committed-burst-size ]

By default, GTS is not configured on an interface.

Configuring the rate limit

Configuring the rate limit for an interface

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Configure the rate limit for the interface.

¡ qos lr outbound cir committed-information-rate [ cbs committed-burst-size ]

By default, no rate limit is configured on an interface.

Display and maintenance commands for traffic policing, GTS, and rate limit

Execute display commands in any view.

Task	Command
Display QoS and ACL resource usage.	display qos-acl resource [ slot slot-number ]
Display traffic behavior configuration.	display traffic behavior user-defined [ behavior-name ]
Display CAR configuration and statistics on an interface.	display qos car interface [ interface-type interface-number ]
Display GTS configuration and statistics for interfaces.	display qos gts interface [ interface-type interface-number [ slot slot-number ] ]
Display rate limit configuration and statistics for interfaces or PWs.	display qos lr interface [ interface-type interface-number ]

Configuring congestion management

About congestion management

Cause, negative results, and countermeasure of congestion

Congestion occurs on a link or node when traffic size exceeds the processing capability of the link or node. It is typical of a statistical multiplexing network and can be caused by link failures, insufficient resources, and various other causes.

Figure 10 shows two typical congestion scenarios.

Figure 10 Traffic congestion scenarios

Congestion produces the following negative results:

· Increased delay and jitter during packet transmission.

· Decreased network throughput and resource use efficiency.

· Network resource (memory, in particular) exhaustion and even system breakdown.

Congestion is unavoidable in switched networks and multiuser application environments. To improve the service performance of your network, take measures to manage and control it.

The key to congestion management is defining a resource dispatching policy to prioritize packets for forwarding when congestion occurs.

Congestion management methods

Congestion management uses queuing and scheduling algorithms to classify and sort traffic leaving a port.

The device supports the following queuing mechanisms:

· SP.

· WRR.

· WFQ.

SP queuing

SP queuing is designed for mission-critical applications that require preferential service to reduce the response delay when congestion occurs.

Figure 11 SP queuing

In Figure 11, SP queuing classifies eight queues on a port into eight classes, numbered 7 to 0 in descending priority order.

SP queuing schedules the eight queues in the descending order of priority. SP queuing sends packets in the queue with the highest priority first. When the queue with the highest priority is empty, it sends packets in the queue with the second highest priority, and so on. You can assign mission-critical packets to a high priority queue to make sure they are always served first. Common service packets can be assigned to low priority queues to be transmitted when high priority queues are empty.

The disadvantage of SP queuing is that packets in the lower priority queues cannot be transmitted if packets exist in the higher priority queues. In the worst case, lower priority traffic might never get serviced.

WRR queuing

WRR queuing schedules all the queues in turn to ensure that every queue is served for a certain time, as shown in Figure 12.

Figure 12 WRR queuing

Assume a port provides eight output queues. WRR assigns each queue a weight value (represented by w7, w6, w5, w4, w3, w2, w1, or w0). The weight value of a queue decides the proportion of resources assigned to the queue. On a 100 Mbps port, you can set the weight values to 50, 30, 10, 10, 50, 30, 10, and 10 for w7 through w0. In this way, the queue with the lowest priority can get a minimum of 5 Mbps of bandwidth. WRR solves the problem that SP queuing might fail to serve packets in low-priority queues for a long time.

Another advantage of WRR queuing is that when the queues are scheduled in turn, the service time for each queue is not fixed. If a queue is empty, the next queue will be scheduled immediately. This improves bandwidth resource use efficiency.

WRR queuing includes the following types:

· Basic WRR queuing—Contains multiple queues. You can set the weight for each queue, and WRR schedules these queues based on the user-defined parameters in a round robin manner.

· Group-based WRR queuing—All the queues are scheduled by WRR. You can divide output queues to WRR priority queue group 1 and WRR priority queue group 2. Round robin queue scheduling is performed for group 1 first. If group 1 is empty, round robin queue scheduling is performed for group 2.

Only WRR group 1 is supported in the current software version.

On an interface enabled with group-based WRR queuing, you can assign queues to the SP group. Queues in the SP group are scheduled with SP. The SP group has higher scheduling priority than the WRR groups.

WFQ queuing

Figure 13 WFQ queuing

WFQ is similar to WRR. WFQ queuing includes basic WFQ queuing and group-based WFQ queuing. Only WFQ group 1 is supported in the current software version.

On an interface with group-based WFQ queuing enabled, you can also assign queues to the SP group. Queues in the SP group are scheduled with SP. The difference is that WFQ enables you to set guaranteed bandwidth that a WFQ queue can get during congestion.

SP+WFQ queuing schedules traffic in the following order:

1. Schedules the traffic conforming to the minimum guaranteed bandwidth of each queue in the WFQ group.

2. Schedules the queues in the SP group based on their priorities.

3. Schedules the traffic in each queue in the WFQ group according to the configured weights when all queues in the SP group are empty.

Congestion management tasks at a glance

To configure hardware congestion management, perform the following tasks:

· Configuring queuing on an interface

¡ Configuring SP queuing

¡ Configuring WRR queuing

¡ Configuring WFQ queuing

¡ Configuring SP+WRR queuing

¡ Configuring SP+WFQ queuing

· Configuring a queue scheduling profile

Configuring queuing on an interface

Configuring SP queuing

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Configure SP queuing.

qos sp

By default, an interface uses SP queuing.

Configuring WRR queuing

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Enable WRR queuing.

qos wrr { byte-count | weight }

By default, an interface uses SP queuing.

4. Assign a queue to a WRR group, and configure scheduling parameters for the queue.

qos wrr queue-id group 1 { byte-count | weight } schedule-value

By default, all queues on a WRR-enabled interface belong to WRR group 1, and the scheduling weight of a queue is its queue ID plus 1.

Configuring WFQ queuing

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Enable WFQ queuing.

qos wfq { byte-count | weight }

By default, an interface uses SP queuing.

4. Assign a queue to a WFQ group, and configure scheduling parameters for the queue.

qos wfq queue-id group 1 { byte-count | weight } schedule-value

By default, all queues on a WFQ-enabled interface belong to WFQ group 1 and have a scheduling weight of 1.

Configuring SP+WRR queuing

Restrictions and guidelines

To configure the scheduling weight, you must specify the same scheduling unit as specified when enabling WRR queuing.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Enable byte-count or packet-count WRR queuing.

qos wrr { byte-count | weight }

By default, an interface uses SP queuing.

4. Assign a queue to the SP group.

qos wrr queue-id group sp

By default, all queues on a WRR-enabled interface belong to WRR group 1, and the scheduling weight of a queue is its queue ID plus 1.

5. Assign a queue to a WRR group, and configure a scheduling weight for the queue.

qos wrr queue-id group 1 { byte-count | weight } schedule-value

By default, all queues on a WRR-enabled interface belong to WRR group 1, and the scheduling weight of a queue is its queue ID plus 1.

Configuring SP+WFQ queuing

Restrictions and guidelines

To configure the scheduling weight, you must specify the same scheduling unit as specified when enabling WFQ queuing.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type interface-number

3. Enable byte-count or packet-count WFQ queuing.

qos wfq { byte-count | weight }

By default, an interface uses SP queuing.

4. Assign a queue to the SP group.

qos wfq queue-id group sp

By default, all queues on a WFQ-enabled interface belong to WFQ group 1, and the scheduling weight of a queue is its queue ID plus 1.

5. Assign a queue to a WFQ queue scheduling group, and configure a scheduling weight for the queue.

qos wfq queue-id group 1 { byte-count | weight } schedule-value

By default, all queues on a WFQ-enabled interface belong to WFQ group 1 and have a scheduling weight of 1.

6. (Optional.) Set the minimum guaranteed bandwidth for a WFQ queue.

qos bandwidth queue queue-id min bandwidth-value

By default, the minimum guaranteed bandwidth for a WFQ queue is 64 kbps.

Configuring a queue scheduling profile

About queue scheduling profiles

In a queue scheduling profile, you can configure scheduling parameters for each queue. By applying the queue scheduling profile to an interface, you can implement congestion management on the interface.

Queue scheduling profiles support three queue scheduling algorithms: SP, WRR, and WFQ. In a queue scheduling profile, you can configure SP+WRR or SP+WFQ. For information about each scheduling algorithm, see "About congestion management." When SP and WRR groups are configured in a queue scheduling profile, Figure 14 shows the scheduling order.

Figure 14 Queue scheduling profile configured with both SP and WRR

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· Queue 7 has the highest priority in the SP group. Its packets are sent preferentially.

· Queue 6 has the second highest priority in the SP group. Packets in queue 6 are sent when queue 7 is empty.

· Queue 3, queue 4, and queue 5 are scheduled according to their weights. When queue 7 and queue 6 are empty, WRR group 1 is scheduled.

· Queue 1 and queue 2 are scheduled according to their weights. WRR group 2 is scheduled when queue 7 through queue 3 are empty.

· Queue 0 has the lowest priority, and it is scheduled when all other queues are empty.

Restrictions and guidelines for queue scheduling profile configuration

When you configure a queue scheduling profile, follow these restrictions and guidelines:

· You can modify the scheduling parameters in a queue scheduling profile already applied to an interface.

· A queue scheduling profile can be applied to a Layer 2 or Layer 3 Ethernet interface.

Configuring a queue scheduling profile

1. Enter system view.

system-view

2. Create a queue scheduling profile and enter queue scheduling profile view.

qos qmprofile profile-name

3. (Optional.) Configure queue scheduling parameters.

¡ Configure a queue to use SP.

queue queue-id sp

¡ Configure a queue to use WRR.

queue queue-id wrr group group-id { weight | byte-count } schedule-value

¡ Configure a queue to use WFQ.

queue queue-id wfq group group-id { weight | byte-count } schedule-value

By default, all queues in a queue scheduling profile are SP queues.

Applying a queue scheduling profile

1. Enter system view.

system-view

2. Enter queue scheduling profile view.

qos qmprofile profile-name

3. Apply the queue scheduling profile.

¡ Execute the following commands in sequence to apply the queue scheduling profile to an interface.

interface interface-type interface-number

qos apply qmprofile profile-name

By default, no queue scheduling profile is applied to an interface.

Example: Configuring a queue scheduling profile

Network configuration

Configure a queue scheduling profile to meet the following requirements on HundredGigE 1/0/1:

· Queue 7 has the highest priority, and its packets are sent preferentially.

· Queue 4, queue 5, and queue 6 are in WRR group 1 and scheduled according to their weights, which are 1, 5, and 10, respectively. When queue 7 is empty, WRR group 1 is scheduled.

· Queue 1, queue 2, and queue 3 are in WRR group 2 and scheduled according to their weights, which are 1, 10, and 20, respectively. When queue 4, queue 5, queue 6, and queue 7 are all empty, WRR group 2 is scheduled.

· Queue 0 has the lowest priority. Queue 0 is scheduled when all the other queues are empty.

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

# Enter system view.

<Sysname> system-view

# Create a queue scheduling profile named qm1.

[Sysname] qos qmprofile qm1

[Sysname-qmprofile-qm1]

# Configure queue 7 to use SP queuing.

[Sysname-qmprofile-qm1] queue 7 sp

# Assign queue 4, queue 5, and queue 6 to WRR group 1, with the weight of 1, 5, and 10, respectively.

[Sysname-qmprofile-qm1] queue 4 wrr group 1 weight 1

[Sysname-qmprofile-qm1] queue 5 wrr group 1 weight 5

[Sysname-qmprofile-qm1] queue 6 wrr group 1 weight 10

# Assign queue 1, queue 2, and queue 3 to WRR group 2, with the weight of 1, 10, and 20, respectively.

[Sysname-qmprofile-qm1] queue 1 wrr group 2 weight 1

[Sysname-qmprofile-qm1] queue 2 wrr group 2 weight 10

[Sysname-qmprofile-qm1] queue 3 wrr group 2 weight 20

# Configure queue 0 to use SP queuing.

[Sysname-qmprofile-qm1] queue 0 sp

[Sysname-qmprofile-qm1] quit

# Apply queue scheduling profile qm1 to HundredGigE 1/0/1.

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] qos apply qmprofile qm1

After the configuration is completed, HundredGigE 1/0/1 performs queue scheduling as specified in queue scheduling profile qm1.

Display and maintenance commands for congestion management

Execute display commands in any view.

Task	Command
Display queuing configuration and statistics for interfaces.	display qos queue interface [ interface-type interface-number ]
Display SP queuing configuration.	display qos queue sp interface [ interface-type interface-number ]
Display WRR queuing configuration.	display qos queue wrr interface [ interface-type interface-number ]
Display WFQ queuing configuration.	display qos queue wfq interface [ interface-type interface-number ]
Display the configuration of queue scheduling profiles.	display qos qmprofile configuration [ profile-name ] [ slot slot-number ]
Display the queue scheduling profiles applied to interfaces.	display qos qmprofile interface [ interface-type interface-number [ slot slot-number ] ]

Configuring congestion avoidance

About congestion avoidance

Avoiding congestion before it occurs is a proactive approach to improving network performance. As a flow control mechanism, congestion avoidance:

· Actively monitors network resources (such as queues and memory buffers).

· Drops packets when congestion is expected to occur or deteriorate.

When dropping packets from a source end, congestion avoidance cooperates with the flow control mechanism at the source end to regulate the network traffic size. The combination of the local packet drop policy and the source-end flow control mechanism implements the following functions:

· Maximizes throughput and network use efficiency.

· Minimizes packet loss and delay.

Tail drop

Congestion management techniques drop all packets that are arriving at a full queue. This tail drop mechanism results in global TCP synchronization. If packets from multiple TCP connections are dropped, these TCP connections go into the state of congestion avoidance and slow start to reduce traffic. However, traffic peak occurs later. Consequently, the network traffic jitters all the time.

RED and WRED

You can use Random Early Detection (RED) or Weighted Random Early Detection (WRED) to avoid global TCP synchronization.

Both RED and WRED avoid global TCP synchronization by randomly dropping packets. When the sending rates of some TCP sessions slow down after their packets are dropped, other TCP sessions remain at high sending rates. Link bandwidth is efficiently used, because TCP sessions at high sending rates always exist.

The RED or WRED algorithm sets an upper threshold and lower threshold for each queue, and processes the packets in a queue as follows:

· When the queue size is shorter than the lower threshold, no packet is dropped.

· When the queue size reaches the upper threshold, all subsequent packets are dropped.

· When the queue size is between the lower threshold and the upper threshold, the received packets are dropped at random. The drop probability in a queue increases along with the queue size under the maximum drop probability.

If the current queue size is compared with the upper threshold and lower threshold to determine the drop policy, burst traffic is not fairly treated. To solve this problem, WRED compares the average queue size with the upper threshold and lower threshold to determine the drop probability.

The average queue size reflects the queue size change trend but is not sensitive to burst queue size changes, and burst traffic can be fairly treated.

When WFQ queuing is used, you can set the following parameters for packets with different precedence values to provide differentiated drop policies:

· Exponent for average queue size calculation.

· Upper threshold.

· Lower threshold.

· Drop probability.

When FIFO, PQ, or CQ is used, you can set the following parameters for each queue to provide differentiated drop policies:

· Exponent for average queue size calculation.

· Upper threshold.

· Lower threshold.

· Drop probability.

Relationship between WRED and queuing mechanisms

Figure 15 Relationship between WRED and queuing mechanisms

Through combining WRED with WFQ, the flow-based WRED can be realized. Each flow has its own queue after classification.

· A flow with a smaller queue size has a lower packet drop probability.

· A flow with a larger queue size has a higher packet drop probability.

In this way, the benefits of the flow with a smaller queue size are protected.

ECN

By dropping packets, WRED alleviates the influence of congestion on the network. However, the network resources for transmitting packets from the sender to the device which drops the packets are wasted. When congestion occurs, it is a better idea to perform the following actions:

· Inform the sender of the congestion status.

· Have the sender proactively slow down the packet sending rate or decrease the window size of packets.

This better utilizes the network resources.

RFC 2482 defined an end-to-end congestion notification mechanism named Explicit Congestion Notification (ECN). ECN uses the DS field in the IP header to mark the congestion status along the packet transmission path. An ECN-capable terminal can determine whether congestion occurs on the transmission path according to the packet contents. Then, it adjusts the packet sending speed to avoid deteriorating congestion. ECN defines the last two bits (ECN field) in the DS field of the IP header as follows:

· Bit 6 indicates whether the sending terminal device supports ECN, and is called the ECN-Capable Transport (ECT) bit.

· Bit 7 indicates whether the packet has experienced congestion along the transmission path, and is called the Congestion Experienced (CE) bit.

For more information about the DS field, see "Appendixes."

In actual applications, the following packets are considered as packets that an ECN-capable endpoint transmits:

· Packets with ECT set to 1 and CE set to 0.

· Packets with ECT set to 0 and CE set to 1.

After you enable ECN on a device, the device processes an incoming packet that enters an output queue as follows:

· When the average queue size is below the lower threshold, the device forwards the packet without modifying the ECN field

· When the average queue size is between the lower threshold and the upper threshold:

¡ If the ECN field is 00, the packet comes from an ECN-incapable endpoint, and the device determines whether to drop the packet according to the drop probability.

¡ If the ECN field is 01 or 10, the packet comes from an ECN-capable endpoint, and the device determines whether to modify the ECN field according to the drop probability and then forwards the packet. All packets will not be dropped.

¡ If the ECN field is 11, the packet has experienced congestion along the transmission path, and the device forwards the packet without modifying the ECN field.

· When the average queue size is above the upper threshold:

¡ If the ECN field is 00, the packet comes from an ECN-incapable endpoint, and the device drops the packet.

¡ If the ECN field is 11, the packet has experienced congestion along the transmission path, and the device forwards the packet without modifying the ECN field.

WRED configuration approaches

WRED parameters

Determine the following parameters before configuring WRED:

· Upper threshold and lower threshold—When the average queue size is smaller than the lower threshold, packets are not dropped. When the average queue size is between the lower threshold and the upper threshold, the packets are dropped at random. The longer the queue, the higher the drop probability. When the average queue size exceeds the upper threshold, subsequent packets are dropped.

· Drop precedence—A parameter used for packet drop. The value 0 corresponds to green packets, the value 1 corresponds to yellow packets, and the value 2 corresponds to red packets. Red packets are dropped preferentially.

· Exponent for average queue size calculation—The greater the exponent, the less sensitive the average queue size is to real-time queue size changes. The formula for calculating the average queue size is:

Average queue size = ( previous average queue size x (1 – 2–n) ) + (current queue size x 2–n), where n is the exponent.

· Drop probability—Drop probability in percentage. The greater the value, the higher the drop probability.

Configuring and applying a queue-based WRED table

Restrictions and guidelines

One WRED table can be applied to multiple interfaces. You can modify the parameters of a WRED table applied to an interface, but you cannot delete the WRED table.

Procedure

1. Enter system view.

system-view

2. Create a WRED table and enter its view.

qos wred queue table table-name

3. (Optional.) Set the WRED exponent for average queue size calculation.

queue queue-id weighting-constant exponent

The default setting is 9.

4. (Optional.) Configure the other WRED parameters.

queue queue-id [ drop-level drop-level ] low-limit low-limit high-limit high-limit [ discard-probability discard-prob ]

By default, the lower limit is 250, the higher limit is 1000, and the drop probability value is 10.

5. (Optional.) Enable ECN for a queue.

queue queue-id ecn

By default, ECN is disabled for a queue.

6. Return to system view.

quit

7. Enter interface view.

interface interface-type interface-number

8. Apply the WRED table to the interface.

qos wred apply [ table-name ]

By default, no WRED table is applied to an interface, and tail drop is used on an interface.

Example: Configuring and applying a queue-based WRED table

Network configuration

Apply a WRED table to HundredGigE 1/0/2, so that the packets are dropped as follows when congestion occurs:

· For the interface to preferentially forward higher-priority traffic, set a lower drop probability for a queue with a greater queue number. Set different drop parameters for queue 0, queue 3, and queue 7.

· Drop packets according to their colors.

¡ In queue 0, set the drop probability to 25%, 50%, and 75% for green, yellow, and red packets, respectively.

¡ In queue 3, set the drop probability to 5%, 10%, and 25% for green, yellow, and red packets, respectively.

¡ In queue 7, set the drop probability to 1%, 5%, and 10% for green, yellow, and red packets, respectively.

· Enable ECN for queue 7.

Procedure

# Configure a queue-based WRED table, and set different drop parameters for packets with different drop levels in different queues.

<Sysname> system-view

[Sysname] qos wred queue table queue-table1

[Sysname-wred-table-queue-table1] queue 0 drop-level 0 low-limit 128 high-limit 512 discard-probability 25

[Sysname-wred-table-queue-table1] queue 0 drop-level 1 low-limit 128 high-limit 512 discard-probability 50

[Sysname-wred-table-queue-table1] queue 0 drop-level 2 low-limit 128 high-limit 512 discard-probability 75

[Sysname-wred-table-queue-table1] queue 3 drop-level 0 low-limit 256 high-limit 640 discard-probability 5

[Sysname-wred-table-queue-table1] queue 3 drop-level 1 low-limit 256 high-limit 640 discard-probability 10

[Sysname-wred-table-queue-table1] queue 3 drop-level 2 low-limit 256 high-limit 640 discard-probability 25

[Sysname-wred-table-queue-table1] queue 7 drop-level 0 low-limit 512 high-limit 1024 discard-probability 1

[Sysname-wred-table-queue-table1] queue 7 drop-level 1 low-limit 512 high-limit 1024 discard-probability 5

[Sysname-wred-table-queue-table1] queue 7 drop-level 2 low-limit 512 high-limit 1024 discard-probability 10

[Sysname-wred-table-queue-table1] queue 7 ecn

[Sysname-wred-table-queue-table1] quit

# Apply the queue-based WRED table to HundredGigE 1/0/2.

[Sysname] interface hundredgige 1/0/2

[Sysname-HundredGigE1/0/2] qos wred apply queue-table1

[Sysname-HundredGigE1/0/2] quit

Display and maintenance commands for WRED

Execute display commands in any view.

Task	Command
Display WRED configuration and statistics for an interface.	display qos wred interface [ interface-type interface-number ]
Display the configuration of a WRED table or all WRED tables.	display qos wred table [ name table-name ]

Configuring traffic filtering

About traffic filtering

You can filter in or filter out traffic of a class by associating the class with a traffic filtering action. For example, you can filter packets sourced from an IP address according to network status.

Restrictions and guidelines: Traffic filtering configuration

A traffic filtering action takes effect only when a QoS policy is applied to an interface or globally.

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured.

For more information about configuring match criteria, see ACL and QoS Command Reference.

c. Return to system view.

quit

3. Define a traffic behavior.

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Configure the traffic filtering action.

filter { deny | permit }

By default, no traffic filtering action is configured.

c. Return to system view.

quit

4. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos policy policy-name

b. Associate the traffic class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

5. Apply the QoS policy.

For more information, see "Applying the QoS policy."

By default, no QoS policy is applied.

6. (Optional.) Execute the display traffic behavior command in any view to display the traffic filtering configuration.

Traffic filtering configuration examples

Example: Configuring traffic filtering

Network configuration

As shown in Figure 16, configure traffic filtering on HundredGigE 1/0/1 to deny the incoming packets with destination port number 21.

Figure 16 Network diagram

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Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

# Create advanced ACL 3000, and configure a rule to match packets with destination port number 21.

<Device> system-view

[Device] acl advanced 3000

[Device-acl-ipv4-adv-3000] rule 0 permit tcp destination-port eq 21

[Device-acl-ipv4-adv-3000] quit

# Create a traffic class named classifier_1, and use ACL 3000 as the match criterion in the traffic class.

[Device] traffic classifier classifier_1

[Device-classifier-classifier_1] if-match acl 3000

[Device-classifier-classifier_1] quit

# Create a traffic behavior named behavior_1, and configure the traffic filtering action to drop packets.

[Device] traffic behavior behavior_1

[Device-behavior-behavior_1] filter deny

[Device-behavior-behavior_1] quit

# Create a QoS policy named policy, and associate traffic class classifier_1 with traffic behavior behavior_1 in the QoS policy.

[Device] qos policy policy

[Device-qospolicy-policy] classifier classifier_1 behavior behavior_1

[Device-qospolicy-policy] quit

# Apply QoS policy policy to the incoming traffic of HundredGigE 1/0/1.

[Device] interface hundredgige 1/0/1

[Device-HundredGigE1/0/1] qos apply policy policy inbound

Configuring protocol packet rate limiting

About protocol packet rate limiting

The protocol packet processing rate of a CPU is limited. When a large number of protocol packets are sent to the CPU, the CPU might be occupied by the protocol packets and cannot process other tasks. The protocol packet rate limiting feature limits the rate of protocol packets sent to the CPU, and it guarantees the normal operation of the CPU.

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match match-criteria

By default, no match criteria are configured.

For more information, see the if-match command in ACL and QoS Command Reference.

c. Return to system view.

quit

3. Define a traffic behavior.

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Configure protocol packet rate limiting.

packet-rate value

By default, protocol packet rate limiting is not configured.

c. Return to system view.

quit

4. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos policy policy-name

b. Associate the class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a class is not associated with any behavior.

c. Return to system view.

quit

5. Apply the QoS policy to a control plane.

For more information, see "Applying the QoS policy to a control plane."

By default, no QoS policy is applied to a control plane.

6. (Optional.) Execute the display traffic behavior command in any view to display the protocol packet rate limiting configuration.

Protocol packet rate limiting configuration examples

Example: Configuring protocol packet rate limiting

Network configuration

As shown in Figure 17, limit the rate of DHCP protocol packets sent to the CPU of the device to 500 pps.

Figure 17 Network diagram

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

# Create a traffic class named classifier_1 and configure the class to match DHCP protocol packets.

<Device> system-view

[Device] traffic classifier classifier_1

[Device-classifier-classifier_1] if-match control-plane protocol dhcp

[Device-classifier-classifier_1] quit

# Create a traffic behavior named behavior_1 and configure the behavior to limit the packet rate to 500 pps.

[Device] traffic behavior behavior_1

[Device-behavior-behavior_1] packet-rate 500

[Device-behavior-behavior_1] quit

# Create a QoS policy named and associate class classifier_1 with behavior behavior_1 in the policy.

[Device] qos policy policy

[Device-qospolicy-policy] classifier classifier_1 behavior behavior_1

[Device-qospolicy-policy] quit

# Apply QoS policy policy to the control plane.

[Device] control-plane slot 1

[Device-cp] qos apply policy policy inbound

Configuring priority marking

About priority marking

Priority marking sets the priority fields or flag bits of packets to modify the priority of packets. For example, you can use priority marking to set IP precedence or DSCP for a class of IP packets to control the forwarding of these packets.

To configure priority marking to set the priority fields or flag bits for a class of packets, perform the following tasks:

1. Configure a traffic behavior with a priority marking action.

2. Associate the traffic class with the traffic behavior.

Priority marking can be used together with priority mapping. For more information, see "Configuring priority mapping."

Configuring priority marking

Restrictions and guidelines

A traffic marking action takes effect only when a QoS policy is applied to an interface, VLAN, control plane, or globally.

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured.

For more information about the if-match command, see ACL and QoS Command Reference.

c. Return to system view.

quit

3. Define a traffic behavior.

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Configure a priority marking action.

For configurable priority marking actions, see the remark commands in ACL and QoS Command Reference.

c. Return to system view.

quit

4. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos [ remarking ] policy policy-name

b. Associate the traffic class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

5. Apply the QoS policy.

For more information, see "Applying the QoS policy."

By default, no QoS policy is applied.

6. (Optional.) Execute the display traffic behavior command in any view to display the priority marking configuration.

Priority marking configuration examples

Example: Configuring priority marking

Network configuration

As shown in Figure 18, configure priority marking on the device to meet the following requirements:

Traffic source	Destination	Processing priority
Host A, B	Data server	High
Host A, B	Mail server	Medium
Host A, B	File server	Low

Figure 18 Network diagram

‌

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

# Create advanced ACL 3000, and configure a rule to match packets with destination IP address 192.168.0.1.

<Device> system-view

[Device] acl advanced 3000

[Device-acl-ipv4-adv-3000] rule permit ip destination 192.168.0.1 0

[Device-acl-ipv4-adv-3000] quit

# Create advanced ACL 3001, and configure a rule to match packets with destination IP address 192.168.0.2.

[Device] acl advanced 3001

[Device-acl-ipv4-adv-3001] rule permit ip destination 192.168.0.2 0

[Device-acl-ipv4-adv-3001] quit

# Create advanced ACL 3002, and configure a rule to match packets with destination IP address 192.168.0.3.

[Device] acl advanced 3002

[Device-acl-ipv4-adv-3002] rule permit ip destination 192.168.0.3 0

[Device-acl-ipv4-adv-3002] quit

# Create a traffic class named classifier_dbserver, and use ACL 3000 as the match criterion in the traffic class.

[Device] traffic classifier classifier_dbserver

[Device-classifier-classifier_dbserver] if-match acl 3000

[Device-classifier-classifier_dbserver] quit

# Create a traffic class named classifier_mserver, and use ACL 3001 as the match criterion in the traffic class.

[Device] traffic classifier classifier_mserver

[Device-classifier-classifier_mserver] if-match acl 3001

[Device-classifier-classifier_mserver] quit

# Create a traffic class named classifier_fserver, and use ACL 3002 as the match criterion in the traffic class.

[Device] traffic classifier classifier_fserver

[Device-classifier-classifier_fserver] if-match acl 3002

[Device-classifier-classifier_fserver] quit

# Create a traffic behavior named behavior_dbserver, and configure the action of setting the local precedence value to 4.

[Device] traffic behavior behavior_dbserver

[Device-behavior-behavior_dbserver] remark local-precedence 4

[Device-behavior-behavior_dbserver] quit

# Create a traffic behavior named behavior_mserver, and configure the action of setting the local precedence value to 3.

[Device] traffic behavior behavior_mserver

[Device-behavior-behavior_mserver] remark local-precedence 3

[Device-behavior-behavior_mserver] quit

# Create a traffic behavior named behavior_fserver, and configure the action of setting the local precedence value to 2.

[Device] traffic behavior behavior_fserver

[Device-behavior-behavior_fserver] remark local-precedence 2

[Device-behavior-behavior_fserver] quit

# Create a QoS policy named policy_server, and associate traffic classes with traffic behaviors in the QoS policy.

[Device] qos policy policy_server

[Device-qospolicy-policy_server] classifier classifier_dbserver behavior behavior_dbserver

[Device-qospolicy-policy_server] classifier classifier_mserver behavior behavior_mserver

[Device-qospolicy-policy_server] classifier classifier_fserver behavior behavior_fserver

[Device-qospolicy-policy_server] quit

# Apply QoS policy policy_server to the incoming traffic of HundredGigE 1/0/1.

[Device] interface hundredgige 1/0/1

[Device-HundredGigE1/0/1] qos apply policy policy_server inbound

[Device-HundredGigE1/0/1] quit

Example: Configuring priority marking and class-based accounting for priority marking verification

Network configuration

As shown in Figure 19, the source IP address of incoming packets on HundredGigE 1/0/1 of Device B is 192.168.0.1, and the DSCP value of the packets is 11.

Configure priority marking and class-based accounting on Device B to verify that priority marking works correctly.

Figure 19 Network diagram

‌

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

# Create basic ACL 2000, and configure a rule to match packets with source IP address 192.168.0.1.

<DeviceB> system-view

[DeviceB] acl basic 2000

[DeviceB-acl-ipv4-basic-2000] rule permit source 192.168.0.1 0

[DeviceB-acl-ipv4-basic-2000] quit

# Create a traffic class named sip, and use ACL 2000 as the match criterion in the traffic class.

[DeviceB] traffic classifier sip

[DeviceB-classifier-sip] if-match acl 2000

[DeviceB-classifier-sip] quit

# Create a traffic class named dscp50, and use DSCP 50 as the match criterion in the traffic class.

[DeviceB] traffic classifier dscp50

[DeviceB-classifier-dscp50] if-match dscp 50

[DeviceB-classifier-dscp50] quit

# Create a traffic behavior named r, and configure the action of setting the DSCP value to 50.

[DeviceB] traffic behavior r

[DeviceB-behavior-r] remark dscp 50

[DeviceB-behavior-r] quit

# Create a traffic behavior named a, and configure a class-based accounting action.

[DeviceB] traffic behavior a

[DeviceB-behavior-a] accounting packet

[DeviceB-behavior-a] quit

# Create a marking-type QoS policy named policy_r, and associate traffic class sip with traffic behavior r in the QoS policy.

[DeviceB] qos remarking policy policy_r

[DeviceB-qospolicy-policy_r] classifier sip behavior r

[DeviceB-qospolicy-policy_r] quit

# Create an accounting-type QoS policy named policy_a, and associate traffic class dscp50 with traffic behavior a in the QoS policy.

[DeviceB] qos accounting policy policy_a

[DeviceB-qospolicy-policy_a] classifier dscp50 behavior a

[DeviceB-qospolicy-policy_a] quit

# Apply QoS policy policy_r to the incoming traffic of HundredGigE 1/0/1.

[DeviceB] interface hundredgige 1/0/1

[DeviceB-HundredGigE1/0/1] qos apply remarking policy policy_r inbound

[DeviceB-HundredGigE1/0/1] quit

# Apply QoS policy policy_a to the outgoing traffic of HundredGigE 1/0/1.

[DeviceB] interface hundredgige 1/0/1

[DeviceB-HundredGigE1/0/1] qos apply accounting policy policy_a outbound

[DeviceB-HundredGigE1/0/1] quit

Verifying the configuration

# Display information about the marking-type QoS policy.

[DeviceB] display qos policy user-defined remarking

User-defined QoS policy information:

Marking policy: policy_r (ID 100)

Classifier: sip (ID 0)

Behavior: r

Marking:

Remark dscp 50

# Display information about the accounting-type QoS policy.

[DeviceB] display qos policy user-defined accounting

User-defined QoS policy information:

Accounting policy: policy_a (ID 101)

Classifier: dscp50 (ID 0)

Behavior: a

Accounting enable: Packet

20 (Packets)

The output shows that the accounting action works correctly.

Configuring nesting

About nesting

Nesting adds a VLAN tag to the matching packets to allow the VLAN-tagged packets to pass through the corresponding VLAN. For example, you can add an outer VLAN tag to packets from a customer network to a service provider network. This allows the packets to pass through the service provider network by carrying a VLAN tag assigned by the service provider.

Restrictions and guidelines: Nesting configuration

An outer VLAN tag adding action takes effect only when a QoS policy is applied to an interface, VLAN, or globally.

For a QoS policy containing a nesting action to take effect, make sure both the downlink port and uplink port permit the single-tagged packets matching the QoS policy. The double-tagged packets are forwarded in the device based on the inner VLAN tag.

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured for a traffic class.

For more information about the match criteria, see the if-match command in ACL and QoS Command Reference.

c. Return to system view.

quit

3. Define a traffic behavior.

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Configure an outer VLAN tag adding action.

nest top-most vlan vlan-id

By default, no outer VLAN tag adding action is configured for a traffic behavior.

c. Return to system view.

quit

4. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos policy policy-name

b. Associate the traffic class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

5. Apply the QoS policy.

For more information, see "Applying the QoS policy."

By default, no QoS policy is applied.

6. (Optional.) Execute the display traffic behavior command in any view to display the nesting configuration.

Nesting configuration examples

Example: Configuring nesting

Network configuration

As shown in Figure 20:

· Site 1 and Site 2 in VPN A are two branches of a company. They use VLAN 5 to transmit traffic.

· Because Site 1 and Site 2 are located in different areas, the two sites use the VPN access service of a service provider. The service provider assigns VLAN 100 to the two sites.

Configure nesting, so that the two branches can communicate through the service provider network.

Figure 20 Network diagram

‌

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

1. Configuring PE 1:

# Create a traffic class named test to match traffic with VLAN ID 5.

<PE1> system-view

[PE1] traffic classifier test

[PE1-classifier-test] if-match service-vlan-id 5

[PE1-classifier-test] quit

# Configure an action to add outer VLAN tag 100 in traffic behavior test.

[PE1] traffic behavior test

[PE1-behavior-test] nest top-most vlan 100

[PE1-behavior-test] quit

# Create a QoS policy named test, and associate class test with behavior test in the QoS policy.

[PE1] qos policy test

[PE1-qospolicy-test] classifier test behavior test

[PE1-qospolicy-test] quit

# Configure the downlink port (HundredGigE 1/0/1) as a hybrid port, assign the port to VLAN 5 as a tagged member, and assign the port to VLAN 100 as an untagged member.

[PE1] interface hundredgige 1/0/1

[PE1-HundredGigE1/0/1] port link-type hybrid

[PE1-HundredGigE1/0/1] port hybrid vlan 5 tagged

[PE1-HundredGigE1/0/1] port hybrid vlan 100 untagged

# Apply QoS policy test to the incoming traffic of HundredGigE 1/0/1.

[PE1-HundredGigE1/0/1] qos apply policy test inbound

[PE1-HundredGigE1/0/1] quit

# Configure the uplink port (HundredGigE 1/0/2) as a trunk port, and assign it to VLAN 5 and VLAN 100.

[PE1] interface hundredgige 1/0/2

[PE1-HundredGigE1/0/2] port link-type trunk

[PE1-HundredGigE1/0/2] port trunk permit vlan 5 100

[PE1-HundredGigE1/0/2] quit

2. Configuring PE 2:

Configure PE 2 in the same way PE 1 is configured.

Configuring traffic redirecting

About traffic redirecting

Traffic redirecting redirects packets matching the specified match criteria to a location for processing.

You can redirect packets to the following destinations:

· CPU.

· Interface.

Restrictions and guidelines: Traffic redirecting configuration

· A traffic redirecting action takes effect only when a QoS policy is applied to the inbound direction of an interface, VLANs, or globally.

· If you execute the redirect command multiple times in the same traffic behavior, the most recent configuration takes effect.

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured for a traffic class.

For more information about the match criteria, see the if-match command in ACL and QoS Command Reference.

c. Return to system view.

quit

3. Define a traffic behavior.

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Configure a traffic redirecting action. Choose one option as needed:

redirect { cpu | interface interface-type interface-number }

By default, no traffic redirecting action is configured for a traffic behavior.

c. Return to system view.

quit

4. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos policy policy-name

b. Associate the traffic class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

5. Apply the QoS policy.

For more information, see "Applying the QoS policy."

By default, no QoS policy is applied.

6. (Optional.) Display traffic redirecting configuration.

display traffic behavior user-defined [ behavior-name ]

This command is available in any view.

Traffic redirecting configuration examples

Example: Configuring traffic redirecting

Network configuration

As shown in Figure 21:

· Device A is connected to Device B through two links. Device A and Device B are each connected to other devices.

· HundredGigE 1/0/2 of Device A is a trunk port and belongs to VLAN 200 and VLAN 201.

· HundredGigE 1/0/2 of Device A and HundredGigE 1/0/2 of Device B belong to VLAN 200.

· HundredGigE 1/0/3 of Device A and HundredGigE 1/0/3 of Device B belong to VLAN 201.

· On Device A, the IP address of VLAN-interface 200 is 200.1.1.1/24, and that of VLAN-interface 201 is 201.1.1.1/24.

· On Device B, the IP address of VLAN-interface 200 is 200.1.1.2/24, and that of VLAN-interface 201 is 201.1.1.2/24.

Configure the actions of redirecting traffic to an interface to meet the following requirements:

· Packets with source IP address 2.1.1.1 received on HundredGigE 1/0/1 of Device A are forwarded to HundredGigE 1/0/2.

· Packets with source IP address 2.1.1.2 received on HundredGigE 1/0/1 of Device A are forwarded to HundredGigE 1/0/3.

· Other packets received on HundredGigE 1/0/1 of Device A are forwarded according to the routing table.

Figure 21 Network diagram

‌

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

# Create basic ACL 2000, and configure a rule to match packets with source IP address 2.1.1.1.

<DeviceA> system-view

[DeviceA] acl basic 2000

[DeviceA-acl-ipv4-basic-2000] rule permit source 2.1.1.1 0

[DeviceA-acl-ipv4-basic-2000] quit

# Create basic ACL 2001, and configure a rule to match packets with source IP address 2.1.1.2.

[DeviceA] acl basic 2001

[DeviceA-acl-ipv4-basic-2001] rule permit source 2.1.1.2 0

[DeviceA-acl-ipv4-basic-2001] quit

# Create a traffic class named classifier_1, and use ACL 2000 as the match criterion in the traffic class.

[DeviceA] traffic classifier classifier_1

[DeviceA-classifier-classifier_1] if-match acl 2000

[DeviceA-classifier-classifier_1] quit

# Create a traffic class named classifier_2, and use ACL 2001 as the match criterion in the traffic class.

[DeviceA] traffic classifier classifier_2

[DeviceA-classifier-classifier_2] if-match acl 2001

[DeviceA-classifier-classifier_2] quit

# Create a traffic behavior named behavior_1, and configure the action of redirecting traffic to HundredGigE 1/0/2.

[DeviceA] traffic behavior behavior_1

[DeviceA-behavior-behavior_1] redirect interface hundredgige 1/0/2

[DeviceA-behavior-behavior_1] quit

# Create a traffic behavior named behavior_2, and configure the action of redirecting traffic to HundredGigE 1/0/3.

[DeviceA] traffic behavior behavior_2

[DeviceA-behavior-behavior_2] redirect interface hundredgige 1/0/3

[DeviceA-behavior-behavior_2] quit

# Create a QoS policy named policy.

[DeviceA] qos policy policy

# Associate traffic class classifier_1 with traffic behavior behavior_1 in the QoS policy.

[DeviceA-qospolicy-policy] classifier classifier_1 behavior behavior_1

# Associate traffic class classifier_2 with traffic behavior behavior_2 in the QoS policy.

[DeviceA-qospolicy-policy] classifier classifier_2 behavior behavior_2

[DeviceA-qospolicy-policy] quit

# Apply QoS policy policy to the incoming traffic of HundredGigE 1/0/1.

[DeviceA] interface hundredgige 1/0/1

[DeviceA-HundredGigE1/0/1] qos apply policy policy inbound

Configuring aggregate CAR

Restrictions and guidelines: Aggregate CAR configuration

An aggregate CAR action takes effect only when a QoS policy is applied to the inbound direction of an interface, VLANs, or globally.

When a QoS policy containing an aggregation CAR is applied to the inbound direction of multiple interfaces, the actual rate limit that takes effect depends on the interface groups of these interfaces. By default, the actual rate limit that takes effect is the CIR plus the PIR specified in the aggregation CAR action multiplied by the number of involved interface groups. Interfaces on different IRF member devices belong to different port groups. To identify port group information, execute the debug port mapping command for the specified slot in probe view. Interfaces with the same Unit and PipeNum values belong to the same port group

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured.

For configurable match criteria, see the if-match command in ACL and QoS Command Reference.

c. Return to system view.

quit

3. Configure an aggregate CAR action.

qos car car-name aggregative cir committed-information-rate [ cbs committed-burst-size [ ebs excess-burst-size ] ] [ green action | red action | yellow action ] *

qos car car-name aggregative cir committed-information-rate [ cbs committed-burst-size ] pir peak-information-rate [ ebs excess-burst-size ] [ green action | red action | yellow action ] *

By default, no aggregate CAR action is configured.

4. Define a traffic behavior.

a. Enter traffic behavior view.

traffic behavior behavior-name

b. Use the aggregate CAR in the traffic behavior.

car name car-name

By default, no aggregate CAR action is used in a traffic behavior.

5. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos policy policy-name

b. Associate the traffic class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

6. Apply the QoS policy.

For more information, see "Applying the QoS policy."

By default, no QoS policy is applied.

Display and maintenance commands for aggregate CAR

Execute display commands in any view and reset commands in user view.

Task	Command
Display statistics for aggregate CAR actions.	display qos car name [ car-name ]
Clear statistics for aggregate CAR actions.	reset qos car name [ car-name ]

Configuring class-based accounting

About class-based accounting

Class-based accounting collects statistics (in packets or bytes) on a per-traffic class basis. For example, you can define the action to collect statistics for traffic sourced from a certain IP address. By analyzing the statistics, you can determine whether anomalies have occurred and what action to take.

Restrictions and guidelines: Class-based accounting configuration

A class-based accounting action takes effect only when a QoS policy is applied to an interface, VLAN, or control plane.

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured.

For more information about the if-match command, see ACL and QoS Command Reference.

c. Return to system view.

quit

3. Define a traffic behavior.

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Configure an accounting action.

accounting [ byte | packet ] *

By default, no traffic accounting action is configured.

c. Return to system view.

quit

4. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos [ accounting ] policy policy-name

b. Associate the traffic class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

5. Apply the QoS policy.

For more information, see "Applying the QoS policy."

By default, no QoS policy is applied.

6. (Optional.) Display the class-based accounting configuration.

display traffic behavior user-defined [ behavior-name ]

Class-based accounting configuration examples

Example: Configuring class-based accounting

Network configuration

As shown in Figure 22, configure class-based accounting on HundredGigE 1/0/1 to collect statistics for incoming traffic from 1.1.1.1/24.

Figure 22 Network diagram

‌

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

# Create basic ACL 2000, and configure a rule to match packets with source IP address 1.1.1.1.

<Device> system-view

[Device] acl basic 2000

[Device-acl-ipv4-basic-2000] rule permit source 1.1.1.1 0

[Device-acl-ipv4-basic-2000] quit

# Create a traffic class named classifier_1, and use ACL 2000 as the match criterion in the traffic class.

[Device] traffic classifier classifier_1

[Device-classifier-classifier_1] if-match acl 2000

[Device-classifier-classifier_1] quit

# Create a traffic behavior named behavior_1, and configure the class-based accounting action.

[Device] traffic behavior behavior_1

[Device-behavior-behavior_1] accounting

[Device-behavior-behavior_1] quit

# Create a QoS policy named policy, and associate traffic class classifier_1 with traffic behavior behavior_1 in the QoS policy.

[Device] qos policy policy

[Device-qospolicy-policy] classifier classifier_1 behavior behavior_1

[Device-qospolicy-policy] quit

# Apply QoS policy policy to the incoming traffic of HundredGigE 1/0/1.

[Device] interface hundredgige 1/0/1

[Device-HundredGigE1/0/1] qos apply policy policy inbound

[Device-HundredGigE1/0/1] quit

# Display traffic statistics to verify the configuration.

[Device] display qos policy interface hundredgige 1/0/1

Interface: HundredGigE1/0/1

Direction: Inbound

Policy: policy

Classifier: classifier_1

Operator: AND

Rule(s) :

If-match acl 2000

Behavior: behavior_1

Accounting enable:

28529 (Packets)

Configuring queue-based accounting

Configuring interface queue-based accounting

About queue-based accounting

Queue-based accounting collects queue-based traffic statistics for interfaces, such as:

· The total length of a queue.

· The current queue length.

· The total number of packets forwarded.

· The number of per-color packets forwarded.

Procedure

1. Enter system view.

system-view

2. Set the packet counting mode to queue.

statistic mode queue

The default packet counting mode is vsi.

Display and maintenance commands for queue-based accounting

Execute display commands in any view and reset commands in user view.

Task	Command
Display queue-based traffic statistics for interfaces.	display qos queue-statistics interface [ interface-type interface-number [ slot slot-number ] ] outbound
Display the packet counting mode.	display statistic mode
Clear queue-based traffic statistics for interfaces (see Layer 2—LAN Switching Command Reference).	reset counters interface [ interface-type [ interface-number \| interface-number.subnumber ] ]

Configuring QPPB

About QPPB

The QoS Policy Propagation Through the Border Gateway Protocol (QPPB) feature enables you to classify IP packets based on the following attributes:

· BGP community lists.

· Prefix lists.

· BGP AS paths.

Application scenarios

QPPB minimizes the QoS policy configuration and management efforts on the BGP route receiver when the network topology changes. It is suitable for a large-scaled complex network.

The QPPB feature is implemented as follows:

· The BGP route sender preclassifies routes before advertising them.

· The BGP route receiver performs the following operations:

¡ Sets the IP precedence and local QoS ID for the routes.

¡ Takes appropriate QoS actions on the packets that match the routes.

QPPB is used in the following scenarios:

· Traffic classification based on source or destination IP addresses.

· Traffic classification based on IBGP and EBGP within an autonomous system or across multiple autonomous systems.

QPPB fundamentals

QPPB works on the BGP receiver by applying a QoS policy to BGP routes with the same IP precedence or local QoS ID. It depends on the BGP route sender to preclassify routes.

The BGP route sender uses a routing policy to set route attributes for BGP routes before advertising them.

The BGP sender performs the following operations:

· Uses a routing policy to match routes based on these route attributes.

· Sets IP precedence and local QoS ID for the matching routes.

The BGP receiver performs the following operations:

1. Compares the routes with the incoming route policy based on their BGP AS path, prefix, or community attributes.

2. Applies the IP precedence and local QoS ID to the matching routes.

3. Adds the BGP routes and their associated IP precedence and local QoS ID to the routing table.

4. Applies the IP precedence and local QoS ID to the packets sourced from or destined to the IP address in the route.

5. Takes QoS actions on the packets according to the QoS priority settings.

QPPB tasks at a glance

To configure QPPB, perform the following tasks:

1. Configuring the route sender

a. Configuring basic BGP functions

b. (Optional.) Creating a routing policy

2. Configuring the route receiver

a. Configuring basic BGP functions

b. Configuring a routing policy

c. Enabling QPPB on the route receiving interface

Configuring the route sender

Configure the BGP route sender to set route attributes for routes before advertising them.

Configuring basic BGP functions

For more information, see Layer 3—IP Routing Configuration Guide.

Creating a routing policy

Configure a routing policy to classify routes and set route attributes for the route classes. For more information, see Layer 3—IP Routing Configuration Guide.

Configuring the route receiver

Configuring basic BGP functions

For more information, see Layer 3—IP Routing Configuration Guide.

Configuring a routing policy

Configure a routing policy to perform the following operations:

· Match the route attributes set by the route sender.

· Set the IP precedence, local QoS ID, or both for the matching routes.

For more information, see Layer 3—IP Routing Configuration Guide.

Enabling QPPB on the route receiving interface

Restrictions and guidelines

For QPPB to work correctly, you must configure the QoS policy as follows:

· Use the IP precedence or local QoS ID set in the routing policy to match packets.

· Specify the mode qppb-manipulation keyword when associating a traffic behavior with a traffic class.

For more information about QoS policies, see "Configuring a QoS policy."

Procedure

1. Enter system view.

system-view

2. Define a traffic class.

a. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

b. Configure a match criterion.

if-match { ip-precedence ip-precedence-value | qos-local-id local-id-value }

By default, no match criterion is configured.

The IP precedence or local QoS ID must be same as that set in "Configuring a routing policy".

c. Return to system view.

quit

3. Define a traffic behavior.

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Configure an action.

By default, no action is configured.

For configuration commands, see traffic behavior commands in ACL and QoS Command Reference.

c. Return to system view.

quit

4. Define a QoS policy.

a. Create a QoS policy and enter QoS policy view.

qos policy policy-name

b. Associate the traffic class with the traffic behavior in the QoS policy.

classifier classifier-name behavior behavior-name mode qppb-manipulation

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

5. Enter interface view.

interface interface-type interface-number

6. Enable QPPB on the interface.

bgp-policy { destination | source } { ip-prec-map | ip-qos-map } *

By default, QPPB is disabled.

This command applies only to incoming traffic.

7. Apply a QoS policy to the interface.

qos apply policy policy-name inbound

By default, no QoS policy is applied to an interface.

QPPB configuration examples

Example: Configuring QPPB in an IPv4 network

Network configuration

As shown in Figure 23, all devices run BGP.

Configure QPPB so that Device B can perform the following operations:

· Receive routes.

· Set IP precedence values and local QoS IDs according to the routing policy.

· Use the QoS policy to limit the traffic rate to 512000 kbps.

Figure 23 Network diagram

‌

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

1. Configure IP addresses for each interface. (Details not shown.)

2. Configure a BGP connection to Device B, and add the network 1.1.1.0/8 to the BGP routing table on Device A.

<DeviceA> system-view

[DeviceA] bgp 1000

[DeviceA-bgp] peer 168.1.1.2 as-number 2000

[DeviceA-bgp] peer 168.1.1.2 connect-interface hundredgige 1/0/2

[DeviceA-bgp] address-family ipv4

[DeviceA-bgp-ipv4] import-route direct

[DeviceA-bgp-ipv4] peer 168.1.1.2 enable

[DeviceA-bgp-ipv4] quit

[DeviceA-bgp] quit

3. Configure Device B:

# Configure a BGP connection to Device A.

<DeviceB> system-view

[DeviceB] bgp 2000

[DeviceB-bgp] peer 168.1.1.1 as-number 1000

[DeviceB-bgp] peer 168.1.1.1 connect-interface hundredgige 1/0/2

[DeviceB-bgp] address-family ipv4

[DeviceB-bgp-ipv4] peer 168.1.1.1 enable

[DeviceB-bgp-ipv4] peer 168.1.1.1 route-policy qppb import

[DeviceB-bgp-ipv4] quit

[DeviceB-bgp] quit

# Configure the routing policy qppb.

[DeviceB] route-policy qppb permit node 0

[DeviceB-route-policy-qppb-0] apply ip-precedence 1

[DeviceB-route-policy-qppb-0] apply qos-local-id 3

[DeviceB-route-policy-qppb-0] quit

# Enable QPPB on HundredGigE 1/0/2.

[DeviceB] interface hundredgige 1/0/2

[DeviceB-HundredGigE1/0/2] bgp-policy source ip-prec-map ip-qos-map

[DeviceB-HundredGigE1/0/2] quit

# Configure a QoS policy.

[DeviceB] traffic classifier qppb

[DeviceB-classifier-qppb] if-match ip-precedence 1

[DeviceB-classifier-qppb] if-match qos-local-id 3

[DeviceB-classifier-qppb] quit

[DeviceB] traffic behavior qppb

[DeviceB-behavior-qppb] car cir 512000 green pass red discard

[DeviceB-behavior-qppb] quit

[DeviceB] qos policy qppb

[DeviceB-qospolicy-qppb] classifier qppb behavior qppb mode qppb-manipulation

[DeviceB-qospolicy-qppb] quit

# Apply the QoS policy to incoming traffic on HundredGigE 1/0/2.

[DeviceB] interface hundredgige 1/0/2

[DeviceB-HundredGigE1/0/2] qos apply policy qppb inbound

[DeviceB-HundredGigE1/0/2] quit

Verifying the configuration

# Verify that the related route on Device B takes effect.

[DeviceB] display bgp routing-table ipv4 1.1.1.0

BGP local router ID: 168.1.1.2

Local AS number: 2000

Paths: 1 available, 1 best

BGP routing table information of 168.1.1.0/24:

From : 168.1.1.1 (168.1.1.1)

Rely nexthop : 168.1.1.1

Original nexthop: 168.1.1.1

Out interface : HundredGigE1/0/2

Route age : 00h30m12s

OutLabel : NULL

RxPathID : 0x0

TxPathID : 0x0

AS-path : 1000

Origin : incomplete

Attribute value : MED 0, pref-val 0

State : valid, external, best

IP precedence : 1

QoS local ID : 3

Traffic index : N/A

Tunnel policy : NULL

Rely tunnel IDs : N/A

# Display the QoS policy configuration on HundredGigE 1/0/2 of Device B.

[DeviceB] display qos policy interface hundredgige 1/0/2

Interface: HundredGigE1/0/2

Direction: Inbound

Policy: qppb

Classifier: default-class

Mode: qppb-manipulation

Matched : 51 (Packets) 4022 (Bytes)

5-minute statistics:

Forwarded: 0/28 (pps/bps)

Dropped : 0/0 (pps/bps)

Operator: AND

Rule(s) :

If-match any

Behavior: be

-none-

Classifier: qppb

Mode: qppb-manipulation

Matched : 0 (Packets) 0 (Bytes)

5-minute statistics:

Forwarded: 0/0 (pps/bps)

Dropped : 0/0 (pps/bps)

Operator: AND

Rule(s) :

If-match ip-precedence 1

If-match qos-local-id 3

Behavior: qppb

Committed Access Rate:

CIR 512000 (kbps), CBS 32000000 (Bytes), EBS 0 (Bytes)

Green action : pass

Yellow action : pass

Red action : discard

Green packets : 0 (Packets) 0 (Bytes)

Yellow packets: 0 (Packets) 0 (Bytes)

Red packets : 0 (Packets) 0 (Bytes)

Example: Configuring QPPB in an MPLS L3VPN

Network configuration

As shown in Figure 24, all devices run BGP.

Configure QPPB so that Device C can perform the following operations:

· Receive routes.

· Set the QPPB local QoS IDs.

· Use the QoS policy to limit the traffic rate to 200000 kbps in each direction.

Figure 24 Network diagram

‌

Table 3 Interfaces and IP address assignment

Device	Interface	IP address	Device	Interface	IP address
Device A	HGE1/0/1	192.168.1.2/24	Device B	HGE1/0/1	167.1.1.2/24
Device A	HGE1/0/2	167.1.1.1/24	Device B	HGE1/0/2	168.1.1.2/24
Device C	HGE1/0/1	169.1.1.2/24	Device D	HGE1/0/2	169.1.1.1/24
Device C	HGE1/0/2	168.1.1.1/24	Device D	HGE1/0/1	192.168.3.2/24

Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

‌

1. Configure IP addresses for each interface. (Details not shown.)

2. Configure a BGP connection on Device A.

<DeviceA> system-view

[DeviceA] bgp 100

[DeviceA-bgp] peer 167.1.1.2 as-number 200

[DeviceA-bgp] peer 167.1.1.2 connect-interface hundredgige 1/0/2

[DeviceA-bgp] address-family ipv4

[DeviceA-bgp-ipv4] import-route direct

[DeviceA-bgp-ipv4] peer 167.1.1.2 enable

[DeviceA-bgp-ipv4] quit

[DeviceA-bgp] quit

3. Configure Device B:

# Configure a VPN instance.

<DeviceB> system-view

[DeviceB] ip vpn-instance vpn1

[DeviceB-vpn-instance-vpn1] route-distinguisher 200:1

[DeviceB-vpn-instance-vpn1] vpn-target 200:1 export-extcommunity

[DeviceB-vpn-instance-vpn1] vpn-target 200:1 import-extcommunity

[DeviceB-vpn-instance-vpn1] quit

# Configure a BGP connection.

[DeviceB] router id 1.1.1.1

[DeviceB] bgp 200

[DeviceB-bgp] peer 2.2.2.2 as-number 200

[DeviceB-bgp] peer 2.2.2.2 connect-interface loopback 0

[DeviceB-bgp] ip vpn-instance vpn1

[DeviceB-bgp-vpn1] peer 167.1.1.1 as-number 100

[DeviceB-bgp-vpn1] address-family ipv4

[DeviceB-bgp-ipv4-vpn1] peer 167.1.1.1 enable

[DeviceB-bgp-ipv4-vpn1] quit

[DeviceB-bgp] address-family vpnv4

[DeviceB-bgp-vpnv4] peer 2.2.2.2 enable

[DeviceB-bgp-vpnv4] quit

[DeviceB-bgp] quit

# Configure MPLS.

[DeviceB] mpls lsr-id 1.1.1.1

[DeviceB] mpls ldp

[DeviceB-mpls-ldp] quit

# Configure OSPF.

[DeviceB] ospf

[DeviceB-ospf-1] area 0

[DeviceB-ospf-1-area-0.0.0.0] network 1.1.1.1 0.0.0.0

[DeviceB-ospf-1-area-0.0.0.0] network 168.1.1.0 0.0.0.255

[DeviceB-ospf-1-area-0.0.0.0] quit

[DeviceB-ospf-1] quit

# Bind HundredGigE 1/0/1 to VPN instance vpn1.

[DeviceB] interface hundredgige 1/0/1

[DeviceB-HundredGigE1/0/1] ip binding vpn-instance vpn1

[DeviceB-HundredGigE1/0/1] ip address 167.1.1.2 24

[DeviceB-HundredGigE1/0/1] quit

# Enable MPLS on HundredGigE 1/0/2.

[DeviceB] interface hundredgige 1/0/2

[DeviceB-HundredGigE1/0/2] mpls enable

[DeviceB-HundredGigE1/0/2] mpls ldp enable

[DeviceB-HundredGigE1/0/2] quit

4. Configure Device C:

# Configure a VPN instance.

<DeviceC> system-view

[DeviceC] ip vpn-instance vpn1

[DeviceC-vpn-instance-vpn1] route-distinguisher 200:1

[DeviceC-vpn-instance-vpn1] vpn-target 200:1 export-extcommunity

[DeviceC-vpn-instance-vpn1] vpn-target 200:1 import-extcommunity

[DeviceC-vpn-instance-vpn1] quit

# Configure a BGP connection.

[DeviceC] router id 2.2.2.2

[DeviceC] bgp 200

[DeviceC-bgp] peer 1.1.1.1 as-number 200

[DeviceC-bgp] peer 1.1.1.1 connect-interface loopback 0

[DeviceC-bgp] ip vpn-instance vpn1

[DeviceC-bgp-vpn1] peer 169.1.1.1 as-number 300

[DeviceC-bgp-vpn1] address-family ipv4

[DeviceC-bgp-ipv4-vpn1] peer 169.1.1.1 enable

[DeviceC-bgp-ipv4-vpn1] peer 169.1.1.1 route-policy qppb import

[DeviceC-bgp-ipv4-vpn1] quit

[DeviceC-bgp-vpn1] quit

[DeviceC-bgp] address-family vpnv4

[DeviceC-bgp-vpnv4] peer 1.1.1.1 enable

[DeviceC-bgp-vpnv4] peer 1.1.1.1 route-policy qppb import

[DeviceC-bgp-vpnv4] quit

[DeviceC-bgp] quit

# Configure a routing policy.

[DeviceC] route-policy qppb permit node 0

[DeviceC-route-policy-qppb-0] apply qos-local-id 3

[DeviceC-route-policy-qppb-0] quit

# Configure MPLS.

[DeviceC] mpls lsr-id 2.2.2.2

[DeviceC] mpls ldp

[DeviceC-mpls-ldp] quit

# Configure OSPF.

[DeviceC] ospf

[DeviceC-ospf-1] area 0

[DeviceC-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0

[DeviceC-ospf-1-area-0.0.0.0] network 168.1.1.0 0.0.0.255

[DeviceC-ospf-1-area-0.0.0.0] quit

[DeviceC-ospf-1] quit

# Configure a QoS policy.

[DeviceC] traffic classifier qppb

[DeviceC-classifier-qppb] if-match qos-local-id 3

[DeviceC-classifier-qppb] quit

[DeviceC] traffic behavior qppb

[DeviceC-behavior-qppb] car cir 200000 green pass red discard

[DeviceC-behavior-qppb] quit

[DeviceC] qos policy qppb

[DeviceC-qospolicy-qppb] classifier qppb behavior qppb mode qppb-manipulation

[DeviceC-qospolicy-qppb] quit

# Enable MPLS on HundredGigE 1/0/2.

[DeviceC] interface hundredgige 1/0/2

[DeviceC-HundredGigE1/0/2] mpls enable

[DeviceC-HundredGigE1/0/2] mpls ldp enable

# Enable QPPB on HundredGigE 1/0/1 and HundredGigE 1/0/2.

[DeviceC-HundredGigE1/0/2] bgp-policy source ip-qos-map

[DeviceC-HundredGigE1/0/2] quit

[DeviceC] interface hundredgige 1/0/1

[DeviceC-HundredGigE1/0/1] bgp-policy source ip-qos-map

[DeviceC-HundredGigE1/0/1] quit

# Bind HundredGigE 1/0/1 to VPN instance vpn1.

[DeviceC] interface hundredgige 1/0/1

[DeviceC-HundredGigE1/0/1] ip binding vpn-instance vpn1

[DeviceC-HundredGigE1/0/1] ip address 169.1.1.2 24

# Apply QoS policy qppb to the incoming traffic of HundredGigE 1/0/1.

[DeviceC-HundredGigE1/0/1] qos apply policy qppb inbound

[DeviceC-HundredGigE1/0/1] quit

# Apply QoS policy qppb to the incoming traffic of HundredGigE 1/0/2.

[DeviceC] interface hundredgige 1/0/2

[DeviceC-HundredGigE1/0/2] qos apply policy qppb inbound

5. Configure a BGP connection on Device D.

<DeviceD> system-view

[DeviceD] bgp 300

[DeviceD-bgp] peer 169.1.1.2 as-number 200

[DeviceD-bgp] peer 169.1.1.2 connect-interface hundredgige 1/0/2

[DeviceD-bgp] address-family ipv4

[DeviceD-bgp-ipv4] peer 169.1.1.2 enable

[DeviceD-bgp-ipv4] import-route direct

[DeviceD-bgp-ipv4] quit

Verifying the configuration

# Verify that the related routes on Device A take effect.

[DeviceA] display ip routing-table

Destinations : 16 Routes : 16

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

167.1.1.0/24 Direct 0 0 167.1.1.1 HGE1/0/2

167.1.1.0/32 Direct 0 0 167.1.1.1 HGE1/0/2

167.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

167.1.1.255/32 Direct 0 0 167.1.1.1 HGE1/0/2

169.1.1.0/24 BGP 255 0 167.1.1.2 HGE1/0/2

192.168.1.0/24 Direct 0 0 192.168.1.2 HGE1/0/1

192.168.1.0/32 Direct 0 0 192.168.1.2 HGE1/0/1

192.168.1.2/32 Direct 0 0 127.0.0.1 InLoop0

192.168.1.255/32 Direct 0 0 192.168.1.2 HGE1/0/1

192.168.3.0/24 BGP 255 0 167.1.1.2 HGE1/0/2

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

# Verify that the related routes on Device B take effect.

[DeviceB] display ip routing-table

Destinations : 12 Routes : 12

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

1.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

2.2.2.2/32 OSPF 10 1 168.1.1.1 HGE1/0/2

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

168.1.1.0/24 Direct 0 0 168.1.1.2 HGE1/0/2

168.1.1.0/32 Direct 0 0 168.1.1.2 HGE1/0/2

168.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0

168.1.1.255/32 Direct 0 0 168.1.1.2 HGE1/0/2

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

[DeviceB] display ip routing-table vpn-instance vpn1

Destinations : 14 Routes : 14

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

167.1.1.0/24 Direct 0 0 167.1.1.2 HGE1/0/1

167.1.1.0/32 Direct 0 0 167.1.1.2 HGE1/0/1

167.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0

167.1.1.255/32 Direct 0 0 167.1.1.2 HGE1/0/1

169.1.1.0/24 BGP 255 0 2.2.2.2 HGE1/0/2

192.168.1.0/24 BGP 255 0 167.1.1.1 HGE1/0/1

192.168.2.0/24 BGP 255 0 167.1.1.1 HGE1/0/1

192.168.3.0/24 BGP 255 0 2.2.2.2 HGE1/0/2

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

# Verify that the related routes on Device C take effect.

[DeviceC] display ip routing-table

Destinations : 12 Routes : 12

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

1.1.1.1/32 OSPF 10 1 168.1.1.2 HGE1/0/2

2.2.2.2/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

168.1.1.0/24 Direct 0 0 168.1.1.1 HGE1/0/2

168.1.1.0/32 Direct 0 0 168.1.1.1 HGE1/0/2

168.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

168.1.1.255/32 Direct 0 0 168.1.1.1 HGE1/0/2

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

[DeviceC] display ip routing-table vpn-instance vpn1

Destinations : 14 Routes : 14

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

167.1.1.0/24 BGP 255 0 1.1.1.1 HGE1/0/2

169.1.1.0/24 Direct 0 0 169.1.1.2 HGE1/0/1

169.1.1.0/32 Direct 0 0 169.1.1.2 HGE1/0/1

169.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0

169.1.1.255/32 Direct 0 0 169.1.1.2 HGE1/0/1

192.168.1.0/24 BGP 255 0 1.1.1.1 HGE1/0/2

192.168.2.0/24 BGP 255 0 169.1.1.1 HGE1/0/1

192.168.3.0/24 BGP 255 0 169.1.1.1 HGE1/0/1

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

# Verify that the related routes on Device D take effect.

[DeviceD] display ip routing-table

Destinations : 16 Routes : 16

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

167.1.1.0/24 BGP 255 0 169.1.1.2 HGE1/0/2

169.1.1.0/24 Direct 0 0 169.1.1.1 HGE1/0/2

169.1.1.0/32 Direct 0 0 169.1.1.1 HGE1/0/2

169.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

169.1.1.255/32 Direct 0 0 169.1.1.1 HGE1/0/2

192.168.1.0/24 BGP 255 0 169.1.1.2 HGE1/0/2

192.168.3.0/24 Direct 0 0 192.168.3.2 HGE1/0/1

192.168.3.0/32 Direct 0 0 192.168.3.2 HGE1/0/1

192.168.3.2/32 Direct 0 0 127.0.0.1 InLoop0

192.168.3.255/32 Direct 0 0 192.168.3.2 HGE1/0/1

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

# Display the QoS policy configuration in the inbound direction on Device C.

[DeviceC] display qos policy interface inbound

Interface: HundredGigE1/0/1

Direction: Inbound

Policy: qppb

Classifier: default-class

Mode: qppb-manipulation

Matched : 312 (Packets) 18916 (Bytes)

5-minute statistics:

Forwarded: 0/24 (pps/bps)

Dropped : 0/0 (pps/bps)

Operator: AND

Rule(s) :

If-match any

Behavior: be

-none-

Classifier: qppb

Mode: qppb-manipulation

Matched : 0 (Packets) 0 (Bytes)

5-minute statistics:

Forwarded: 0/0 (pps/bps)

Dropped : 0/0 (pps/bps)

Operator: AND

Rule(s) :

If-match qos-local-id 3

Behavior: qppb

Committed Access Rate:

CIR 200000 (kbps), CBS 1250000 (Bytes), EBS 0 (Bytes)

Green action : pass

Yellow action : pass

Red action : discard

Green packets : 0 (Packets) 0 (Bytes)

Yellow packets: 0 (Packets) 0 (Bytes)

Red packets : 0 (Packets) 0 (Bytes)

Interface: HundredGigE1/0/2

Direction: Inbound

Policy: qppb

Classifier: default-class

Mode: qppb-manipulation

Matched : 311 (Packets) 23243 (Bytes)

5-minute statistics:

Forwarded: 0/24 (pps/bps)

Dropped : 0/0 (pps/bps)

Operator: AND

Rule(s) :

If-match any

Behavior: be

-none-

Classifier: qppb

Mode: qppb-manipulation

Matched : 0 (Packets) 0 (Bytes)

5-minute statistics:

Forwarded: 0/0 (pps/bps)

Dropped : 0/0 (pps/bps)

Operator: AND

Rule(s) :

If-match qos-local-id 3

Behavior: qppb

Committed Access Rate:

CIR 200000 (kbps), CBS 12500480 (Bytes), EBS 0 (Bytes)

Green action : pass

Yellow action : pass

Red action : discard

Green packets : 0 (Packets) 0 (Bytes)

Yellow packets: 0 (Packets) 0 (Bytes)

Red packets : 0 (Packets) 0 (Bytes)

Example: Configuring QPPB in an IPv6 network

Network configuration

As shown in Figure 25, all devices run BGP.

Configure QPPB so that Device B can perform the following operations:

· Receive routes.

· Set the QPPB IP precedence value.

· Use the QoS policy to limit the rate of traffic with the IP precedence value to 512000 kbps.

Figure 25 Network diagram

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Procedure

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

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1. Configure IPv6 addresses for each interface. (Details not shown.)

2. Configure BGP on Device A.

<DeviceA> system-view

[DeviceA] bgp 1000

[DeviceA] peer 168::2 as-number 2000

[DeviceA] peer 168::2 connect-interface hundredgige 1/0/2

[DeviceA-bgp] address-family ipv6

[DeviceA-bgp-ipv6] peer 168::2 enable

[DeviceA-bgp-ipv6] import-route direct

[DeviceA-bgp-ipv6] quit

[DeviceA-bgp] quit

3. Configure Device B:

# Configure BGP.

<DeviceB> system-view

[DeviceB] bgp 2000

[DeviceB] peer 168::1 as-number 1000

[DeviceB] peer 168::1 connect-interface hundredgige 1/0/2

[DeviceB-bgp] address-family ipv6

[DeviceB-bgp-ipv6] peer 168::1 enable

[DeviceB-bgp-ipv6] peer 168::1 route-policy qppb import

[DeviceB-bgp-ipv6] quit

[DeviceB-bgp] quit

# Configure a routing policy.

[DeviceB] route-policy qppb permit node 0

[DeviceB-route-policy-qppb-0] apply ip-precedence 4

[DeviceB-route-policy-qppb-0] apply qos-local-id 3

[DeviceB-route-policy-qppb-0] quit

# Enable QPPB on HundredGigE 1/0/1.

[DeviceB] interface hundredgige 1/0/1

[DeviceB-HundredGigE1/0/1] bgp-policy source ip-prec-map ip-qos-map

# Configure a QoS policy.

[DeviceB] traffic classifier qppb

[DeviceB-classifier-qppb] if-match ip-precedence 4

[DeviceB-classifier-qppb] if-match qos-local-id 3

[DeviceB-classifier-qppb] quit

[DeviceB] traffic behavior qppb

[DeviceB-behavior-qppb] car cir 512000 red discard

[DeviceB-behavior-qppb] quit

[DeviceB] qos policy qppb

[DeviceB-qospolicy-qppb] classifier qppb behavior qppb mode qppb-manipulation

[DeviceB-qospolicy-qppb] quit

# Apply the QoS policy to the incoming traffic of HundredGigE 1/0/2.

[DeviceB] interface hundredgige 1/0/2

[DeviceB-HundredGigE1/0/2] qos apply policy qppb inbound

[DeviceB-HundredGigE1/0/2] quit

Verifying the configuration

# Verify that the related routes on Device A take effect.

[DeviceA] display bgp routing-table ipv6 2:: 64

BGP local router ID: 0.0.0.0

Local AS number: 1000

Paths: 1 available, 1 best

BGP routing table information of 168::/64:

Imported route.

Original nexthop: ::

Out interface : HundredGigE 1/0/1

Route age : 00h17m18s

OutLabel : NULL

RxPathID : 0x0

TxPathID : 0x0

AS-path : (null)

Origin : incomplete

Attribute value : MED 0, pref-val 32768

State : valid, local, best

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : NULL

Rely tunnel IDs : N/A

# Verify that the related routes on Device B take effect.

[DeviceB] display bgp routing-table ipv6 1:: 64

BGP local router ID: 0.0.0.0

Local AS number: 2000

Paths: 1 available, 1 best

BGP routing table information of 168::/64:

Imported route.

Original nexthop: ::

Out interface : HundredGigE 1/0/1

Route age : 00h05m17s

OutLabel : NULL

RxPathID : 0x0

TxPathID : 0x0

AS-path : (null)

Origin : incomplete

Attribute value : MED 0, pref-val 32768

State : valid, local, best

IP precedence : 4

QoS local ID : 3

Traffic index : N/A

Tunnel policy : NULL

Rely tunnel IDs : N/A

# Display the configuration and statistics for the QoS policy applied to HundredGigE 1/0/2 on Device C.

[DeviceC] display qos policy interface hundredgige 1/0/2

Interface: HundredGigE1/0/2

Direction: Inbound

Policy: qppb

Classifier: default-class

Mode: qppb-manipulation

Matched : 0 (Packets) 0 (Bytes)

5-minute statistics:

Forwarded: 0/0 (pps/bps)

Dropped : 0/0 (pps/bps)

Operator: AND

Rule(s) :

If-match any

Behavior: be

-none-

Classifier: qppb

Mode: qppb-manipulation

Matched : 0 (Packets) 0 (Bytes)

5-minute statistics:

Forwarded: 0/0 (pps/bps)

Dropped : 0/0 (pps/bps)

Operator: AND

Rule(s) :

If-match ip-precedence 4

If-match qos-local-id 3

Behavior: qppb

Committed Access Rate:

CIR 512000 (kbps), CBS 32000000 (Bytes), EBS 0 (Bytes)

Green action : pass

Yellow action : pass

Red action : discard

Green packets : 0 (Packets) 0 (Bytes)

Yellow packets: 0 (Packets) 0 (Bytes)

Red packets : 0 (Packets) 0 (Bytes)

Appendixes

Appendix A Acronyms

Table 4 Appendix A Acronyms

Acronym	Full spelling
AF	Assured Forwarding
BE	Best Effort
BQ	Bandwidth Queuing
CAR	Committed Access Rate
CBS	Committed Burst Size
CBQ	Class Based Queuing
CE	Congestion Experienced
CIR	Committed Information Rate
CQ	Custom Queuing
DCBX	Data Center Bridging Exchange Protocol
DiffServ	Differentiated Service
DSCP	Differentiated Services Code Point
EBS	Excess Burst Size
ECN	Explicit Congestion Notification
EF	Expedited Forwarding
FIFO	First in First out
FQ	Fair Queuing
GMB	Guaranteed Minimum Bandwidth
GTS	Generic Traffic Shaping
IntServ	Integrated Service
ISP	Internet Service Provider
LLQ	Low Latency Queuing
LSP	Label Switched Path
MPLS	Multiprotocol Label Switching
PE	Provider Edge
PHB	Per Hop Behavior
PIR	Peak Information Rate
PQ	Priority Queuing
PW	Pseudowire
QoS	Quality of Service
QPPB	QoS Policy Propagation Through the Border Gateway Protocol
RED	Random Early Detection
RSVP	Resource Reservation Protocol
RTP	Real-Time Transport Protocol
SP	Strict Priority
ToS	Type of Service
VoIP	Voice over IP
VPN	Virtual Private Network
WFQ	Weighted Fair Queuing
WRED	Weighted Random Early Detection
WRR	Weighted Round Robin

Appendix B Default priority maps

For the default dscp-dscp and exp-dot1p priority maps, an input value yields a target value equal to it.

Table 5 Default dot1p-lp, dot1p-dp, dot1p-dscp priority maps

Input priority value	dot1p-lp map	dot1p-dp map	dot1p-dscp map
dot1p	lp	dp	dscp
0	2	0	0
1	0	0	8
2	1	0	16
3	3	0	24
4	4	0	32
5	5	0	40
6	6	0	48
7	7	0	56

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Table 6 Default dscp-dp, dscp-dot1p, and dscp-exp priority maps

Input priority value	dscp-dp map	dscp-dot1p map	dscp-exp map
dscp	dp	dot1p	exp
0 to 7	0	0	0
8 to 15	0	1	1
16 to 23	0	2	2
24 to 31	0	3	3
32 to 39	0	4	4
40 to 47	0	5	5
48 to 55	0	6	6
56 to 63	0	7	7

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Table 7 Default exp-dscp priority map

Input priority value	exp-dscp map
EXP value	dscp
0	0
1	8
2	16
3	24
4	32
5	40
6	48
7	56

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Table 8 Default port priority-local priority map

Port priority	Local precedence
0	0
1	1
2	2
3	3
4	4
5	5
6	6
7	7

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Appendix C Introduction to packet precedence

IP precedence and DSCP values

Figure 26 ToS and DS fields

As shown in Figure 26, the ToS field in the IP header contains 8 bits. The first 3 bits (0 to 2) represent IP precedence from 0 to 7. According to RFC 2474, the ToS field is redefined as the differentiated services (DS) field. A DSCP value is represented by the first 6 bits (0 to 5) of the DS field and is in the range 0 to 63. The remaining 2 bits (6 and 7) are reserved.

Table 9 IP precedence

IP precedence (decimal)	IP precedence (binary)	Description
0	000	Routine
1	001	priority
2	010	immediate
3	011	flash
4	100	flash-override
5	101	critical
6	110	internet
7	111	network

Table 10 DSCP values

DSCP value (decimal)	DSCP value (binary)	Description
46	101110	ef
10	001010	af11
12	001100	af12
14	001110	af13
18	010010	af21
20	010100	af22
22	010110	af23
26	011010	af31
28	011100	af32
30	011110	af33
34	100010	af41
36	100100	af42
38	100110	af43
8	001000	cs1
16	010000	cs2
24	011000	cs3
32	100000	cs4
40	101000	cs5
48	110000	cs6
56	111000	cs7
0	000000	be (default)

802.1p priority

802.1p priority lies in the Layer 2 header. It applies to occasions where Layer 3 header analysis is not needed and QoS must be assured at Layer 2.

Figure 27 An Ethernet frame with an 802.1Q tag header

As shown in Figure 27, the 4-byte 802.1Q tag header contains the 2-byte tag protocol identifier (TPID) and the 2-byte tag control information (TCI). The value of the TPID is 0x8100. Figure 28 shows the format of the 802.1Q tag header. The Priority field in the 802.1Q tag header is called 802.1p priority, because its use is defined in IEEE 802.1p. Table 11 shows the values for 802.1p priority.

Figure 28 802.1Q tag header

Table 11 Description on 802.1p priority

802.1p priority (decimal)	802.1p priority (binary)	Description
0	000	best-effort
1	001	background
2	010	spare
3	011	excellent-effort
4	100	controlled-load
5	101	video
6	110	voice
7	111	network-management

EXP values

The EXP field is in MPLS labels for MPLS QoS purposes. As shown in Figure 29, the EXP field is 3-bit long and is in the range of 0 to 7.

Figure 29 MPLS label structure

08-ACL and QoS Configuration Guide

QoS techniques in a network

Defining a traffic class

Defining a traffic behavior

Defining a QoS policy

Restrictions and guidelines

Procedure

Restrictions and guidelines

Procedure

Applying the QoS policy to VLANs

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

Applying the QoS policy to a control plane

About this task

Procedure

Priority mapping process

Priority mapping tasks at a glance

Configuring a priority map

About this task

Procedure

Procedure

About this task

Procedure

Network configuration

Procedure

Configuring traffic policing, GTS, and rate limit

Traffic evaluation and token buckets

Token bucket features

Evaluating traffic with the token bucket

Complicated evaluation

Configuring traffic policing

Restrictions and guidelines

Procedure

Restrictions and guidelines

Procedure

Configuring GTS

Procedure

Configuring the rate limit

Display and maintenance commands for traffic policing, GTS, and rate limit

SP queuing

WRR queuing

WFQ queuing

Configuring queuing on an interface

Configuring SP+WRR queuing

Restrictions and guidelines

Procedure

Restrictions and guidelines

Procedure

Restrictions and guidelines for queue scheduling profile configuration

Network configuration

Procedure

Network configuration

Procedure

Network configuration

Procedure

Network configuration

Procedure

Restrictions and guidelines

Procedure

Priority marking configuration examples

Network configuration

Procedure

Network configuration

Procedure

Verifying the configuration