Contents

QoS overview· 1

QoS service models· 1

Best-effort service model 1

IntServ model 1

DiffServ model 1

QoS techniques in a network· 1

QoS processing flow in a device· 2

QoS configuration approaches· 3

Configuring a QoS policy· 4

About QoS policies· 4

QoS policy tasks at a glance· 4

Defining a traffic class· 4

Defining a traffic behavior 4

Defining a QoS policy· 5

Applying the QoS policy· 5

Application destinations· 5

Restrictions and guidelines for applying a QoS policy· 5

Applying the QoS policy to an interface· 5

Applying the QoS policy to VLANs· 6

Applying the QoS policy globally· 6

Applying the QoS policy to a control plane· 7

Display and maintenance commands for QoS policies· 8

Setting the exclusive bandwidth on an interface· 10

About setting the exclusive bandwidth· 10

Restrictions and guidelines· 10

Procedure· 10

Display and maintenance commands for exclusive bandwidth· 10

Configuring priority mapping· 11

About priority mapping· 11

About priorities· 11

Priority maps· 11

Priority mapping configuration methods· 12

Priority mapping process· 12

Restrictions and guidelines· 14

Priority mapping tasks at a glance· 14

Configuring a priority map· 15

About priority maps· 15

Configuring an uncolored priority map· 16

Configuring a colored priority map· 16

Configuring a flexible priority map for an interface· 17

Configuring the priority trust mode· 18

Changing the port priority of an interface· 19

Configuring colored primap· 19

Display and maintenance commands for priority mapping· 20

Priority mapping configuration examples· 21

Example: Configuring a priority trust mode· 21

Example: Configuring priority mapping tables and priority marking· 22

Configuring traffic policing, GTS, and rate limit 25

About traffic policing, GTS, and rate limit 25

Traffic evaluation and token buckets· 25

Traffic policing· 26

GTS· 27

Rate limit 28

Configuring traffic policing· 29

Traffic policing configuration approaches· 29

Configuring traffic policing by using the MQC approach· 29

Configuring traffic policing for a user profile· 31

Configuring traffic policing for a control plane· 31

Configuring GTS· 32

Configuring queue-based GTS· 32

Configuring GTS for a user group profile· 32

Configuring GTS for a session group profile· 33

Configuring the rate limit for an interface· 33

Configuring traffic permission by using the MQC approach· 34

Display and maintenance commands for traffic policing, GTS, and rate limit 34

Traffic policing, GTS, and rate limit configuration examples· 35

Example: Configuring traffic policing and GTS· 35

Configuring hardware congestion management 39

About hardware congestion management 39

SP queuing· 39

WRR queuing· 40

WFQ queuing· 41

CBQ queuing· 41

Hardware congestion management tasks at a glance· 42

Configuring queuing on an interface· 42

Configuring SP queuing· 42

Configuring WRR queuing· 42

Configuring WFQ queuing· 43

Configuring SP+WRR queuing· 43

Configuring CBQ·· 44

Restrictions and guidelines· 44

Configure AF and the minimum guaranteed bandwidth· 44

Configuring EF and the guaranteed bandwidth· 45

Configuring WFQ·· 46

Example: Configuring CBQ·· 48

Configuring a queue scheduling profile· 50

About queue scheduling profiles· 50

Restrictions and guidelines for queue scheduling profile configuration· 51

Configuring a queue scheduling profile· 51

Applying a queue scheduling profile· 52

Example: Configuring a queue scheduling profile· 52

Display and maintenance commands for hardware congestion management 53

Configuring congestion avoidance· 55

About congestion avoidance· 55

Tail drop· 55

RED and WRED·· 55

Relationship between WRED and queuing mechanisms· 56

ECN·· 56

WRED parameters· 57

Configuring and applying a queue-based WRED table· 58

Restrictions and guidelines· 58

Procedure· 58

Example: Configuring and applying a queue-based WRED table· 59

Display and maintenance commands for WRED·· 60

Configuring traffic filtering· 61

About traffic filtering· 61

Restrictions and guidelines: Traffic filtering configuration· 61

Procedure· 61

Traffic filtering configuration examples· 62

Example: Configuring traffic filtering· 62

Configuring priority marking· 64

About priority marking· 64

Configuring priority marking by using the MQC approach· 64

Priority marking configuration examples· 65

Example: Configuring priority marking· 65

Example: Configuring priority marking and class-based accounting for priority marking verification· 67

Configuring traffic redirecting· 70

About traffic redirecting· 70

Restrictions and guidelines: Traffic redirecting configuration· 70

Procedure· 71

Traffic redirecting configuration examples· 72

Example: Configuring traffic redirecting to the next hop· 72

Configuring global CAR· 74

About global CAR·· 74

Configuring aggregate CAR by using the MQC approach· 74

Display and maintenance commands for global CAR·· 75

Global CAR configuration examples· 75

Example: Configuring aggregate CAR·· 75

Configuring class-based accounting· 77

About class-based accounting· 77

Restrictions and guidelines: Class-based accounting configuration· 77

Procedure· 77

Class-based accounting configuration examples· 78

Example: Configuring class-based accounting· 78

Configuring queue-based accounting· 80

About queue-based accounting· 80

Procedure· 80

Display and maintenance commands for queue-based accounting· 80

Configuring QPPB· 81

About QPPB· 81

Application scenarios· 81

QPPB fundamentals· 81

QPPB tasks at a glance· 82

Configuring the route sender 82

Configuring basic BGP functions· 82

Creating a routing policy· 82

Configuring the route receiver 82

Configuring basic BGP functions· 82

Configuring a routing policy· 82

Enabling QPPB on the route receiving interface· 82

QPPB configuration examples· 83

Example: Configuring QPPB in an IPv4 network· 83

Example: Configuring QPPB in an MPLS L3VPN·· 86

Example: Configuring QPPB in an IPv6 network· 93

Appendixes· 97

Appendix A Acronyms· 97

Appendix B Default priority maps· 98

Uncolored priority maps· 98

Colored priority maps· 99

Appendix C Introduction to packet precedence· 101

IP precedence and DSCP values· 101

802.1p priority· 103

EXP values· 104

 

QoS overview

In data communications, Quality of Service (QoS) provides differentiated service guarantees for diversified traffic in terms of bandwidth, delay, jitter, and drop rate, all of which can affect QoS.

QoS manages network resources and prioritizes traffic to balance system resources.

The following section describes typical QoS service models and widely used QoS techniques.

QoS service models

This section describes several typical QoS service models.

Best-effort service model

The best-effort model is a single-service model. The best-effort model is not as reliable as other models and does not guarantee delay-free delivery.

The best-effort service model is the default model for the Internet and applies to most network applications. It uses the First In First Out (FIFO) queuing mechanism.

IntServ model

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.        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

1.        Enter system view.

system-view

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

qos 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 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.

 

Parameter	Description
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 routing policy configuration in Layer 3—IP Routing Configuration Guide.

 

Applying the QoS policy

Application destinations

You can apply a QoS policy to the following destinations:

·          Interface—The QoS policy takes effect on the traffic sent or received on the interface.

·          VLAN—The QoS policy takes effect on the traffic sent or received on all ports in the VLAN.

·          Globally—The QoS policy takes effect on the traffic sent or received on all ports.

·          Control plane—The QoS policy takes effect on the traffic received on the control plane.

·          User profile—The QoS policy takes effect on the traffic sent or received by the online users of the user profile.

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 (except that it is applied to a user profile). If a traffic class uses an ACL for traffic classification, you can delete or modify the ACL.

Applying the QoS policy to an interface

Restrictions and guidelines

A QoS policy can be applied to multiple interfaces. A maximum of two QoS policies with different priorities and names can be applied to the inbound direction of an interface. Only one QoS policy can be applied to the outbound direction 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. The most common local packets include link maintenance, IS-IS, OSPF, RIP, BGP, LDP, RSVP, and SSH packets.

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

On the following cards, if you apply QoS policies separately to an aggregate interface and a member port of the aggregate interface, the QoS policy applied to the aggregate interface effect:

·          CEPC.

·          CSPEX.

·          CSPC-GE16XP4L-E, CSPC-GE24L-E, and CSPC-GP24GE8XP2L-E.

The QoS policy applied to the member port takes effect after it leaves the aggregation group.

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 policy policy-name { inbound | outbound } [ preorder preorder-value ] [ share-mode ]

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

Applying the QoS policy to VLANs

About QoS policy application to VLANs

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, including VLANs created by GVRP.

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 the main processing unit or 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 | outbound }

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

Applying the QoS policy globally

About global QoS policy application

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

Restrictions and guidelines

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 the main processing unit or 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 policy policy-name global { inbound | outbound } [ preorder preorder-value ]

By default, no QoS policy is applied globally.

A QoS policy applied in the outbound direction globally does not take effect on CSPC (except CSPC-GE16XP4L-E, CSPC-GE24L-E, and CSPC-GP24GE8XP2L-E) or CMPE-1104 cards.

Applying the QoS policy to a control plane

About the data plane and control plane

A device provides the data plane and the control plane.

·          Data plane—The units at the data 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 data plane units, the control plane units allow for great packet processing flexibility but have lower throughput.

When the data 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 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.

In standalone mode:

control-plane slot slot-number

In IRF mode:

control-plane chassis chassis-number 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
(In standalone mode.) Display traffic class configuration.	display traffic classifier user-defined [ classifier-name ] [ slot slot-number ]
(In IRF mode.) Display traffic class configuration.	display traffic classifier user-defined [ classifier-name ] [ chassis chassis-number slot slot-number ]
(In standalone mode.) Display traffic behavior configuration.	display traffic behavior user-defined [ behavior-name ] [ slot slot-number ]
(In IRF mode.) Display traffic behavior configuration.	display traffic behavior user-defined [ behavior-name ] [ chassis chassis-number slot slot-number ]
(In standalone mode.) Display QoS and ACL resource usage.	display qos-acl resource [ slot slot-number ]
(In IRF mode.) Display QoS and ACL resource usage.	display qos-acl resource [ chassis chassis-number slot slot-number ]
(In standalone mode.) Display QoS policy configuration.	display qos policy user-defined [ policy-name [ classifier classifier-name ] ] [ slot slot-number ]
(In IRF mode.) Display QoS policy configuration.	display qos policy user-defined [ policy-name [ classifier classifier-name ] ] [ chassis chassis-number slot slot-number ]
(In standalone mode.) Display information about QoS policies applied to interfaces.	display qos policy interface [ interface-type interface-number ] [ slot slot-number | all ] [ inbound | outbound ]
(In IRF mode.) Display information about QoS policies applied to interfaces.	display qos policy interface [ interface-type interface-number ] [ chassis chassis-number slot slot-number | all ] [ inbound | outbound ]
(In standalone mode.) Display information about QoS policies applied to user profiles.	display qos policy user-profile [ name profile-name ] [ user-id user-id ] [ slot slot-number ] [ inbound | outbound ]
(In IRF mode.) Display information about QoS policies applied to user profiles.	display qos policy user-profile [ name profile-name ] [ user-id user-id ] [ chassis chassis-number slot slot-number ] [ inbound | outbound ]
(In standalone mode.) Display information about QoS policies applied to VLANs.	display qos vlan-policy { name policy-name | vlan [ vlan-id ] } [ slot slot-number ] [ inbound | outbound ]
(In IRF mode.) Display information about QoS policies applied to VLANs.	display qos vlan-policy { name policy-name | vlan [ vlan-id ] } [ chassis chassis-number slot slot-number ] [ inbound | outbound ]
(In standalone mode.) Display information about QoS policies applied globally.	display qos policy global [ slot slot-number ] [ inbound | outbound ]
(In IRF mode.) Display information about QoS policies applied globally.	display qos policy global [ chassis chassis-number slot slot-number ] [ inbound | outbound ]
(In standalone mode.) Display information about QoS policies applied to a control plane.	display qos policy control-plane slot slot-number
(In IRF mode.) Display information about QoS policies applied to a control plane.	display qos policy control-plane chassis chassis-number slot slot-number
(In standalone mode.) Display information about the predefined QoS policy applied to the control plane.	display qos policy control-plane pre-defined [ slot slot-number ]
(In IRF mode.) Display information about the predefined QoS policy applied to the control plane.	display qos policy control-plane pre-defined [ chassis chassis-number 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 policy global [ inbound | outbound ]
(In standalone mode.) Clear the statistics for the QoS policy applied to a control plane.	reset qos policy control-plane slot slot-number
(In IRF mode.) Clear the statistics for the QoS policy applied to a control plane.	reset qos policy control-plane chassis chassis-number slot slot-number

 

 

Setting the exclusive bandwidth on an interface

About setting the exclusive bandwidth

The exclusive bandwidth on an interface is reserved for specific features and cannot be shared with other features. The amount of exclusive bandwidth is deducted from the interface bandwidth.

Restrictions and guidelines

The exclusive bandwidth feature is mutually exclusive with the HQoS feature. If one feature has been configured on an interface, the other feature cannot be configured successfully.

Procedure

1.        Enter system view.

system-view

2.        Enter interface view.

interface interface-type interface-number

3.        Set the exclusive bandwidth on the interface.

qos exclusive-bandwidth bandwidth-value

By default, no exclusive bandwidth is set on an interface.

Display and maintenance commands for exclusive bandwidth

Execute display commands in any view.

 

Task	Command
(Distributed devices in standalone mode.) Display exclusive bandwidth settings for interfaces.	display qos exclusive-bandwidth interface [ interface-type interface-number ] outbound [ slot slot-number ]
(Distributed devices in IRF mode.) Display exclusive bandwidth settings for interfaces.	display qos exclusive-bandwidth interface [ interface-type interface-number ] outbound [ chassis chassis-number 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 switch 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

 

The switch 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

 

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

Restrictions and guidelines

If all member ports of a Layer 3 aggregate interface are on CSPEX (except CSPEX-1204 and CSPEX-1104-E) and CEPC cards, you can configure a flexible priority map, the auto priority trust mode, and the port priority for the Layer 3 aggregate interface or subinterface. The flexible priority map, the auto priority trust mode, and the port priority settings for the Layer 3 aggregate interface or subinterface takes priority over these settings on its member ports.

Priority mapping tasks at a glance

To configure priority mapping, perform the following tasks:

1.        (Optional.) Configuring a priority map

¡  Configuring an uncolored priority map

¡  Configuring a colored priority map

¡  Configuring a flexible priority map for an interface

2.        Configure a priority mapping method:

¡  Configuring the priority trust mode

¡  Changing the port priority of an interface

¡  Configuring colored primap

Configuring a priority map

About priority maps

Table 1 shows the priority maps provided by the device. These priority maps can be colored or uncolored.

You can use colored priority maps if the packets are colored by traffic policing. You can use uncolored priority maps if the packets are not colored by traffic policing. For how traffic policing processes and colors packets, see "About traffic policing, GTS, and rate limit."

Table 1 Priority maps

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

 

Configuring an uncolored priority map

1.        Enter system view.

system-view

2.        Enter priority map view.

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

CSPC (except CSPC-GE16XP4L-E, CSPC-GE24L-E, and CSPC-GP24GE8XP2L-E) and CMPE-1104 cards do not support the following priority maps:

¡  dot1p-dot1p

¡  dot1p-dscp

¡  dot1p-exp

¡  dscp-exp

¡  dscp-lp

¡  exp-dscp

¡  exp-dp

¡  exp-exp

¡  exp-lp

3.        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 "Uncolored priority maps."

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

Configuring a colored priority map

1.        Enter system view.

system-view

2.        Enter colored priority map view.

qos map-table color { green | yellow | red } { inbound { dot1p-dot1p | dot1p-dp | dot1p-dscp | dot1p-exp | dot1p-lp | dscp-dot1p | dscp-dp | dscp-dscp | dscp-exp | dscp-lp | exp-dot1p | exp-dp | exp-dscp | exp-exp | exp-lp } | outbound { dot1p-dot1p | dot1p-dscp | dot1p-exp | dscp-dot1p | dscp-dscp | dscp-exp | exp-dot1p | exp-dscp | exp-exp } }

CSPC (except CSPC-GE16XP4L-E, CSPC-GE24L-E, and CSPC-GP24GE8XP2L-E) and CMPE-1104 cards do not support colored priority maps.

3.        Configure mappings for the colored priority map.

import import-value-list export export-value

By default, the default colored priority maps are used. For more information, see "Colored priority maps."

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

Configuring a flexible priority map for an interface

About flexible priority maps

An uncolored or colored priority map takes effect on the device globally. A flexible priority map can be applied on a per-interface basis for controlling packet scheduling and forwarding more accurately.

Restrictions and guidelines

If you both configure a priority map in priority map view and apply a flexible priority map to an interface, the flexible priority map takes effect on the interface.

Procedure

1.        Enter system view.

system-view

2.        Create a flexible priority map and enter its view.

qos map-table name map-table-name

3.        Configure mappings for the flexible priority map.

{ dot1p-dot1p | dot1p-dp | dot1p-dscp | dot1p-exp | dot1p-lp | dscp-dot1p | dscp-dp | dscp-dscp | dscp-exp | dscp-lp | exp-dot1p | exp-dp | exp-dscp | exp-exp | exp-lp | lp-dot1p | lp-dp | lp-dscp | lp-exp | lp-phb } import import-value-list export export-value

By default, no mapping is configured in a flexible priority map.

If you execute this command multiple times and enter the same input values for one priority map, the most recent configuration takes effect.

4.        Return to system view.

quit

5.        Enter interface view.

interface interface-type interface-number

6.        Apply the flexible priority map to the interface.

qos apply map-table map-table-name [ inbound | outbound ]

If you do not specify a direction, the inbound direction applies. Only one priority map can be applied to one direction of an interface.

Only the following priority maps can be applied to the inbound direction of an interface:

¡  dot1p-dot1p

¡  dot1p-dp

¡  dot1p-dscp

¡  dot1p-exp

¡  dot1p-lp

¡  dscp-dot1p

¡  dscp-dp

¡  dscp-dscp

¡  dscp-exp

¡  dscp-lp

¡  exp-dot1p

¡  exp-dp

¡  exp-dscp

¡  exp-exp

¡  exp-lp

Only the following priority maps can be applied to the outbound direction of an interface:

¡  lp-dot1p

¡  lp-dp

¡  lp-dscp

¡  lp-exp

¡  lp-php

Configuring the priority trust mode

About configuring the priority trust mode

You can configure the device to trust priority fields carried in packets for priority mapping. When you configure the trusted packet priority type on an interface, use the following available keywords:

·          auto—Automatically selects the priority of each received packet according to packet type for mapping.

¡  On CSPC (except CSPC-GE16XP4L-E, CSPC-GE24L-E, and CSPC-GP24GE8XP2L-E) and CMPE-1104 cards:

-      For non-IP packets, the 802.1p priority is used.

-      For IP packets, the IP precedence is used.

-      For MPLS packets, the EXP value is used.

¡  On CSPC-GE16XP4L-E, CSPC-GE24L-E, CSPC-GP24GE8XP2L-E, CSPEX, and CEPC cards:

-      For Layer 2 packets, the 802.1p priority is used.

-      For Layer 3 packets, the IP precedence is used.

-      For MPLS packets, the EXP value is used.

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

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

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

Restrictions and guidelines

On CSPC (except CSPC-GE16XP4L-E, CSPC-GE24L-E, and CSPC-GP24GE8XP2L-E) and CMPE-1104 cards, you must specify the override keyword when configuring the qos trust auto command.

The dot1p, dscp, and inner-dot1p keywords are available only on CSPEX (except CSPEX-1204 and CSPEX-1104-E) and CEPC cards.

When an IP packet enters an MPLS network, the device populates the EXP field with the EXP value derived from a priority map even if the override keyword is not specified.

For a Layer 3 packet, the device overwrites the 802.1p priority value in the packet with the 802.1p priority value derived from a priority map even if the override keyword is not specified.

For an MPLS packet that comes from the public network, he device uses the EXP value in the packet for priority mapping instead of trusting the configured 802.1p or DSCP priority.

Procedure

1.        Enter system view.

system-view

2.        Enter interface view.

interface interface-type interface-number

3.        Configure the priority trust mode.

qos trust { auto | dot1p | dscp | inner-dot1p } [ override ]

By default, a port does not trust any packet priority and uses the port priority based on the packet type for priority mapping.

Changing the port priority of an interface

About port priority

If the auto priority trust mode is not configured, 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 { dot1p | dscp | exp } priority-value

The default setting is 0.

The dot1p, dscp, and exp keywords are available only on CSPC-GE16XP4L-E, CSPC-GE24L-E, CSPC-GP24GE8XP2L-E, CSPEX, and CEPC cards.

Configuring colored primap

About primap

To reassign priority parameters for a traffic class according to a priority mapping table, configure a primap traffic behavior and associate it with the traffic class.

Restrictions and guidelines

The device supports the following application destinations for primap:

·          Interface.

·          VLANs.

·          Globally.

·          Control plane.

·          User profile.

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.

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 CAR 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 CAR action is configured.

c.    Configure the action of assigning priority values to packets using a specified colored priority mapping table.

primap pre-defined color { dot1p-dot1p | dot1p-dp | dot1p-dscp | dot1p-exp | dot1p-lp | dscp-dot1p | dscp-dp | dscp-dscp | dscp-exp | dscp-lp | exp-dot1p | exp-dp | exp-dscp | exp-exp | exp-lp }

By default, no priority mapping action is configured.

d.    (Optional.) Configure the action of assigning drop priority to packets according to packet color.

primap color-map-dp

By default, no priority mapping action is configured.

The packet color-to-drop priority mappings are fixed to red to 2, yellow to 1, and green to 0.

This action can be used only in the outbound direction.

e.    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 behavior with the traffic class.

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.

Display and maintenance commands for priority mapping

Execute display commands in any view.

 

Task	Command
Display priority map configuration.	display qos map-table inbound [ dot1p-dot1p | dot1p-dp | dot1p-dscp | dot1p-exp | dot1p-lp | dscp-dot1p | dscp-dp | dscp-dscp | dscp-exp | dscp-lp | exp-dot1p | exp-dp | exp-dscp | exp-exp | exp-lp ]
Display colored priority map configuration.	display qos map-table color [ green | yellow | red ] { inbound [ dot1p-dot1p | dot1p-dp | dot1p-dscp | dot1p-exp | dot1p-lp | dscp-dot1p | dscp-dp | dscp-dscp | dscp-exp | dscp-lp | exp-dot1p | exp-dp | exp-dscp | exp-exp | exp-lp ] | outbound [ dot1p-dot1p | dot1p-dscp | dot1p-exp | dscp-dot1p | dscp-dscp | dscp-exp | exp-dot1p | exp-dscp | exp-exp ] }
Display flexible priority map configuration.	display qos map-table name [ map-table-name ]
Display flexible priority maps applied to interfaces.	display qos map-table interface [ interface-type interface-number ] [ inbound | outbound ]
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 GigabitEthernet 3/1/3 of Device C is congested.

Figure 5 Network diagram

 

Procedure

# Assign port priority to GigabitEthernet 3/1/1 and GigabitEthernet 3/1/2. Make sure the following requirements are met:

·          The priority of GigabitEthernet 3/1/1 is higher than that of GigabitEthernet 3/1/2.

·          The auto priority trust mode is not configured on GigabitEthernet 3/1/1 or GigabitEthernet 3/1/2.

<DeviceC> system-view

[DeviceC] interface gigabitethernet 3/1/1

[DeviceC-GigabitEthernet3/1/1] qos priority 3

[DeviceC-GigabitEthernet3/1/1] quit

[DeviceC] interface gigabitethernet 3/1/2

[DeviceC-GigabitEthernet3/1/2] qos priority 1

[DeviceC-GigabitEthernet3/1/2] quit

Example: Configuring priority mapping tables and priority marking

Network configuration

As shown in Figure 6:

·          The Marketing department connects to GigabitEthernet 3/1/1 of Device, which sets the DSCP priority of traffic from the Marketing department to 18.

·          The R&D department connects to GigabitEthernet 3/1/2 of Device, which sets the DSCP priority of traffic from the R&D department to 55.

·          The Management department connects to GigabitEthernet 3/1/3 of Device, which sets the DSCP priority of traffic from the Management department to 38.

Configure port priority, 802.1p-to-local mapping table, and priority marking to implement the plan as described in Table 2.

Table 2 Configuration plan

Traffic destination	Traffic priority order	Queuing plan
		Traffic source	Output queue	Queue priority
Public servers	R&D department > Management department > Marketing department	R&D department	6	High
		Management department	4	Medium
		Marketing department	2	Low
Internet	Management department > Marketing department > R&D department	R&D department	2	Low
		Management department	6	High
		Marketing department	3	Medium

 

Figure 6 Network diagram

 

Procedure

1.        Configure trusting port priority:

# Set the port priority of GigabitEthernet 3/1/1 to 18.

<Device> system-view

[Device] interface gigabitethernet 3/1/1

[Device-GigabitEthernet3/1/1] qos priority dscp 18

[Device-GigabitEthernet3/1/1] quit

# Set the port priority of GigabitEthernet 3/1/2 to 55.

[Device] interface gigabitethernet 3/1/2

[Device-GigabitEthernet3/1/2] qos priority dscp 55

[Device-GigabitEthernet3/1/2] quit

# Set the port priority of GigabitEthernet 3/1/3 to 38.

[Device] interface gigabitethernet 3/1/3

[Device-GigabitEthernet3/1/3] qos priority dscp 38

[Device-GigabitEthernet3/1/3] quit

According to the default dscp-lp mapping table, DSCP values 18, 55, 38 correspond to to local precedence values 2, 6, and 4, respectively.

This guarantees the R&D department, Management department, and Marketing department decreased priorities to access the public servers.

2.        Configure priority marking to mark the packets from Management department, Marketing department, and R&D department to the Internet with local precedence values 6, 3, and 2.

This guarantees the Management department, Marketing department, and R&D department decreased priorities to access the Internet.

# Create ACL 3000, and configure a rule to match HTTP packets.

[Device] acl advanced 3000

[Device-acl-adv-3000] rule permit tcp destination-port eq 80

[Device-acl-adv-3000] quit

# Create a traffic class named http, and use ACL 3000 as a match criterion.

[Device] traffic classifier http

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

[Device-classifier-http] quit

# Create a traffic behavior named admin, and configure a marking action for the Management department.

[Device] traffic behavior admin

[Device-behavior-admin] remark local-precedence 6

[Device-behavior-admin] quit

# Create a QoS policy named admin, and associate traffic class http with traffic behavior admin in QoS policy admin.

[Device] qos policy admin

[Device-qospolicy-admin] classifier http behavior admin

[Device-qospolicy-admin] quit

# Apply QoS policy admin to the inbound direction of Gigabitethernet 3/1/3.

[Device] interface gigabitethernet 3/1/3

[Device-Gigabitethernet3/1/3] qos apply policy admin inbound

# Create a traffic behavior named market, and configure a marking action for the Marketing department.

[Device] traffic behavior market

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

[Device-behavior-market] quit

# Create a QoS policy named market, and associate traffic class http with traffic behavior market in QoS policy market.

[Device] qos policy market

[Device-qospolicy-market] classifier http behavior market

[Device-qospolicy-market] quit

# Apply QoS policy market to the inbound direction of Gigabitethernet 3/1/1.

[Device] interface gigabitethernet 3/1/1

[Device-Gigabitethernet3/1/1] qos apply policy market inbound

# Create a traffic behavior named rd, and configure a marking action for the R&D department.

[Device] traffic behavior rd

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

[Device-behavior-rd] quit

# Create a QoS policy named rd, and associate traffic class http with traffic behavior rd in QoS policy rd.

[Device] qos policy rd

[Device-qospolicy-rd] classifier http behavior rd

[Device-qospolicy-rd] quit

# Apply QoS policy rd to the inbound direction of Gigabitethernet 3/1/2.

[Device] interface gigabitethernet 3/1/2

[Device-Gigabitethernet3/1/2] qos apply policy rd inbound

 

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

Traffic policing supports policing the inbound traffic and the outbound traffic.

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 or reset the IP precedence of the packets. Figure 7 shows an example of policing outbound traffic on an interface.

Figure 7 Traffic policing

 

Traffic policing is widely used in policing traffic entering the ISP networks. It can classify the policed traffic and take predefined policing actions on each packet depending on the evaluation result:

·          Forwarding the packet if the evaluation result is "conforming."

·          Dropping the packet if the evaluation result is "excess."

·          Forwarding the packet with its precedence re-marked if the evaluation result is "conforming."

GTS

GTS supports shaping the outbound traffic. GTS limits the outbound 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 8. 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 8 GTS

 

For example, in Figure 9, 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 9 GTS application

 

 

Rate limit

The rate limit of an interface specifies the maximum rate for sending 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 10 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. It is easier to use than traffic policing in controlling the total traffic rate.

Configuring traffic policing

Traffic policing configuration approaches

You can configure traffic policing by using the MQC approach or the non-MQC approach. If both approaches are used, the MQC configuration takes effect.

You can configure the following types of traffic policing by using the non-MQC approach:

·          Traffic policing for a user profile.

·          Traffic policing for a control plane.

Configuring traffic policing by using the MQC approach

Restrictions and guidelines

The device supports the following application destinations for traffic policing:

·          Interface.

·          VLANs.

·          Globally.

·          Control plane.

·          User profile.

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.

Only the pass action is supported for green packets and yellow packets on CSPC-GE16XP4L-E, CSPC-GE24L-E, CSPC-GP24GE8XP2L-E, CSPEX, and CEPC cards.

Only the discard and pass actions are supported for red packets on CSPC-GE16XP4L-E, CSPC-GE24L-E, CSPC-GP24GE8XP2L-E, CSPEX, and CEPC cards.

If you set the cir committed-information-rate option to a value in the range of 1 to 8 kbps on , the actual setting takes effect. If you set this option to a value in the range of 1 to 8 kbps on any other card, 8 kbps always takes effect.

In a traffic policing action applied to a control plane, the supported value range for the cir committed-information-rate option is 8 to 10000 kbps.

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 a user profile

About traffic policing for a user profile

When a user profile is configured, you can perform traffic policing based on users. After a user passes authentication, the authentication server sends the name of the user profile associated with the user to the device. When any user of the user profile logs in, the authentication server automatically applies the CAR parameters configured for the user profile to the user. When the user logs off, the system automatically removes the CAR configuration without manual intervention.

Procedure

1.        Enter system view.

system-view

2.        Enter user profile view.

user-profile profile-name

3.        Configure a CAR policy for the user profile.

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

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

By default, no CAR policy is configured for a user profile.

Configuring traffic policing for a control plane

About traffic policing for a control plane

You can configure the following types of traffic policing for a control plane:

·          Traffic policing for all traffic—Polices all control plane traffic.

·          Online user-based traffic policing—Polices the control plane traffic from all online users.

·          Whitelist-based traffic policing—Polices the control plane traffic that matches the dynamic whitelist by using the system-defined traffic policing parameters.

If multiple types of traffic policing for a control plane are configured, they take effect at the same time. When the control plane is congested, the traffic that matches the dynamic whitelist is preferentially sent to the control plane.

This feature is available only on CSPEX (except CSPEX-1204 and CSPEX-1104-E) and CEPC cards.

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

Procedure

1.        Enter system view.

system-view

2.        Enter control plane view.

In standalone mode:

control-plane slot slot-number

In IRF mode:

control-plane chassis chassis-number slot slot-number

3.        (Optional.) Enable whitelist-based traffic policing.

qos car whitelist [ ipv6 ] enable

By default, whitelist-based traffic policing is enabled, and the device uses the default rate limit values to police matching traffic.

4.        Configure a CAR policy for the control plane.

¡  Configure a CAR policy for all traffic.

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

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

By default, no CAR policy is configured for all traffic.

¡  Configure an online user-based CAR policy.

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

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

By default, no online user-based CAR policy is configured.

Configuring GTS

Configuring queue-based GTS

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.

For this command to take effect on a Layer 3 aggregate interface or subinterface, make sure all its member ports are on CSPEX (except CSPEX-1204 and CSPEX-1104-E) and CEPC cards.

On CSPC-GE16XP4L-E, CSPC-GE24L-E, CSPC-GP24GE8XP2L-E, CSPEX-1104-E, and CSPEX-1204 cards, you cannot configure both queue-based GTS and a queue scheduling profile with WRR queuing for the same interface.

Configuring GTS for a user group profile

About traffic policing for a user group profile

When a user group profile is configured, you can perform GTS based on home users. After a user passes authentication, the authentication server sends the name of the user group profile associated with the user to the device. When any home user of the user group profile logs in, the authentication server automatically applies the GTS parameters configured for the user group profile to the user. When the user logs off, the system automatically removes the GTS configuration without manual intervention.

Restrictions and guidelines

Only the outgoing traffic (traffic received by home users) can be policed.

Procedure

1.        Enter system view.

system-view

2.        Enter user group profile view.

user-group-profile profile-name

3.        Configure GTS for the user group profile.

qos gts [ inbound ] any cir committed-information-rate [ cbs committed-burst-size [ ebs excess-burst-size ] ] [ queue-length queue-length ]

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

By default, GTS is not configured for a user group profile.

The configuration in user group profile view takes effect when the home users come online.

Configuring GTS for a session group profile

About GTS for a session group profile

When a session group profile is configured, you can perform GTS based on home users. After a user passes authentication, the authentication server sends the name of the session group profile associated with the user to the device. When any home user of the session group profile logs in, the authentication server automatically applies the GTS parameters configured for the session group profile to the user. When the user logs off, the system automatically removes the GTS configuration without manual intervention.

This feature is available only on CSPEX (except CSPEX-1104-E) and CEPC cards.

Procedure

1.        Enter system view.

system-view

2.        Enter session group profile view.

user-profile profile-name type session-group

3.        Configure GTS for the session group profile.

qos gts { any | queue queue-id } cir committed-information-rate [ cbs committed-burst-size [ ebs excess-burst-size ] ] [ queue-length queue-length ]

qos gts { any | queue queue-id } cir committed-information-rate [ cbs committed-burst-size ] pir peak-information-rate [ ebs excess-burst-size ] [ queue-length queue-length ]

By default, GTS is not configured for a session group profile.

The configuration in session group profile view takes effect when the home users come online.

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.

For this command to take effect on a Layer 3 aggregate interface or subinterface, make sure all its member ports are on CSPEX (except CSPEX-1204 and CSPEX-1104-E) and CEPC cards.

Configuring traffic permission by using the MQC approach

About traffic permission

Traffic permission allows matching traffic to pass through without performing rate limiting and accounting on the traffic. Traffic permission is supported only for traffic that passes IPoE, portal, or PPPoE authentication.

The device supports the following application destinations for traffic permission:

·          Interface.

·          VLANs.

·          Globally.

·          Control plane.

·          User profile.

Procedure

1.        Enter system view.

system-view

2.        Enter traffic behavior view.

traffic behavior behavior-name

3.        Configure the rate limit for the interface.

free account

By default, no traffic permission action is configured.

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

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

 

Task	Command
(In standalone mode.) Display ACL rules in the dynamic whitelist.	display acl whitelist [ ipv6 ] slot slot-number
(In IRF mode.) Display ACL rules in the dynamic whitelist.	display acl whitelist [ ipv6 ] chassis chassis-number slot slot-number
(In standalone mode.) Display whitelist-based control plane CAR configuration and statistics.	display qos car control-plane whitelist [ ipv6 ] slot slot-number
(In IRF mode.) Display whitelist-based control plane CAR configuration and statistics.	display qos car control-plane whitelist [ ipv6 ] chassis chassis-number slot slot-number
(In standalone mode.) Display QoS and ACL resource usage.	display qos-acl resource [ slot slot-number ]
(In IRF mode.) Display QoS and ACL resource usage.	display qos-acl resource [ chassis chassis-number slot slot-number ]
Display traffic behavior configuration.	display traffic behavior user-defined [ behavior-name ]
(In standalone mode.) Display GTS configuration and statistics for interfaces.	display qos gts interface [ interface-type interface-number [ slot slot-number ] ]
(In IRF mode.) Display GTS configuration and statistics for interfaces.	display qos gts interface [ interface-type interface-number [ chassis chassis-number slot slot-number ] ]
(In standalone mode.) Display queue-based traffic statistics for a home user.	display qos queue-statistics user-id user-id [ slot slot-number ] outbound
(In IRF mode.) Display queue-based traffic statistics for a home user.	display qos queue-statistics user-id user-id [ chassis chassis-number slot slot-number ] outbound
(In standalone mode.) Display rate limit configuration and statistics for interfaces.	display qos lr interface [ interface-type interface-number [ slot slot-number ] ]
(In IRF mode.) Display rate limit configuration and statistics for interfaces.	display qos lr interface [ interface-type interface-number [ chassis chassis-number slot slot-number ] ]
(In standalone mode.) Clear whitelist-based control plane CAR statistics.	reset qos car control-plane whitelist [ ipv6 ] slot slot-number
(In IRF mode.) Clear whitelist-based control plane CAR statistics.	reset qos car control-plane whitelist [ ipv6 ] chassis chassis-number slot slot-number

 

Traffic policing, GTS, and rate limit configuration examples

Example: Configuring traffic policing and GTS

Network configuration

As shown in Figure 11:

·          The server, Host A, and Host B can access the Internet through Router A and Router B.

·          The server, Host A, and GigabitEthernet 3/1/1 of Router A are in the same network segment.

·          Host B and GigabitEthernet 3/1/2 of Router A are in the same network segment.

Perform traffic control for the packets that GigabitEthernet 3/1/1 of Router A receives from the server and Host A using the following guidelines:

·          Limit the rate of packets from the server to 10240 kbps. When the traffic rate is below 10240 kbps, the traffic is forwarded. When the traffic rate exceeds 10240 kbps, the excess packets are marked with DSCP value 0 and then forwarded.

·          Limit the rate of packets from Host A to 25600 kbps. When the traffic rate is below 25600 kbps, the traffic is forwarded. When the traffic rate exceeds 25600 kbps, the excess packets are dropped.

Perform traffic control on GigabitEthernet 3/1/1 and GigabitEthernet 3/1/2 of Router B using the following guidelines:

·          Limit the total incoming traffic rate on GigabitEthernet 3/1/1 to 204800 kbps, and the excess packets are dropped.

·          Limit the outgoing HTTP traffic rate on GigabitEthernet 3/1/2 to 102400 kbps, and the excess packets are dropped.

Figure 11 Network diagram

 

Procedure

1.        Configure Router A:

# Configure ACLs to permit the packets from the server and Host A.

[RouterA] acl basic 2001

[RouterA-acl-ipv4-basic-2001] rule permit source 1.1.1.1 0

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

[RouterA] acl basic 2002

[RouterA-acl-ipv4-basic-2002] rule permit source 1.1.1.2 0

[RouterA-acl-ipv4-basic-2002] quit

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

[RouterA] traffic classifier server

[RouterA-classifier-server] if-match acl 2001

[RouterA-classifier-server] quit

# Create a traffic class named host, and use ACL 2002 as the match criterion.

[RouterA] traffic classifier host

[RouterA-classifier-host] if-match acl 2002

[RouterA-classifier-host] quit

# Create a traffic behavior named server, and configure a traffic policing action (CIR 102400 kbps).

[RouterA] traffic behavior server

[RouterA-behavior-server] car cir 102400 red remark-dscp-pass 0

[RouterA-behavior-server] quit

# Create a traffic behavior named host, and configure a traffic policing action (CIR 25600 kbps).

[RouterA] traffic behavior host

[RouterA-behavior-host] car cir 25600

[RouterA-behavior-host] quit

# Create a QoS policy named car, and associate traffic classes server and host with traffic behaviors server and host in the QoS policy, respectively.

[RouterA] qos policy car

[RouterA-qospolicy-car] classifier server behavior server

[RouterA-qospolicy-car] classifier host behavior host

[RouterA-qospolicy-car] quit

# Apply QoS policy car to the inbound direction of GigabitEthernet 3/1/1.

[RouterA] interface gigabitethernet 3/1/1

[RouterA-GigabitEthernet3/1/1] qos apply policy car inbound

2.        Configure Router B:

# Create ACL 3001, and configure a rule to match HTTP packets.

<RouterB> system-view

[RouterB] acl advanced 3001

[RouterB-acl-ipv4-adv-3001] rule permit tcp destination-port eq 80

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

# Create a traffic class named http, and use ACL 3001 as a match criterion.

[RouterB] traffic classifier http

[RouterB-classifier-http] if-match acl 3001

[RouterB-classifier-http] quit

# Create a traffic class named class, and configure the traffic class to match all packets.

[RouterB] traffic classifier class

[RouterB-classifier-class] if-match any

[RouterB-classifier-class] quit

# Create a traffic behavior named car_inbound, and configure a traffic policing action (CIR 204800 kbps).

[RouterB] traffic behavior car_inbound

[RouterB-behavior-car_inbound] car cir 204800

[RouterB-behavior-car_inbound] quit

# Create a traffic behavior named car_outbound, and configure a traffic policing action (CIR 102400 kbps).

[RouterB] traffic behavior car_outbound

[RouterB-behavior-car_outbound] car cir 102400

[RouterB-behavior-car_outbound] quit

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

[RouterB] qos policy car_inbound

[RouterB-qospolicy-car_inbound] classifier class behavior car_inbound

[RouterB-qospolicy-car_inbound] quit

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

[RouterB] qos policy car_outbound

[RouterB-qospolicy-car_outbound] classifier http behavior car_outbound

[RouterB-qospolicy-car_outbound] quit

# Apply QoS policy car_inbound to the inbound direction of Gigabitethernet 3/1/1.

[RouterB] interface gigabitethernet 3/1/1

[RouterB-Gigabitethernet3/1/1] qos apply policy car_inbound inbound

# Apply QoS policy car_outbound to the outbound direction of Gigabitethernet 3/1/2.

[RouterB] interface gigabitethernet 3/1/2

[RouterB-Gigabitethernet3/1/2] qos apply policy car_outbound outbound