08-ACL and QoS Configuration Guide

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02-QoS configuration
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Contents

QoS overview· 1

QoS service models· 1

Best-effort service model 1

IntServ model 1

DiffServ model 1

QoS techniques overview·· 1

Configuring a QoS policy· 3

Non-MQC approach· 3

MQC approach· 3

Configuration procedure diagram·· 3

Defining a traffic class· 4

Configuration restrictions and guidelines· 4

Configuration procedure· 4

Defining a traffic behavior 6

Defining a QoS policy· 6

Applying the QoS policy· 6

Applying the QoS policy to an interface· 7

Applying the QoS policy to a VLAN·· 7

Applying the QoS policy globally· 8

Displaying and maintaining QoS policies· 8

Configuring priority mapping· 10

Overview·· 10

Introduction to priorities· 10

Priority maps· 10

Priority trust mode on a port 10

Priority mapping process· 11

Priority mapping configuration tasks· 12

Configuring a priority map· 13

Configuring a port to trust packet priority for priority mapping· 13

Changing the port priority of an interface· 14

Displaying and maintaining priority mapping· 14

Priority mapping configuration examples· 14

Priority trust mode configuration example· 14

Priority mapping table and priority marking configuration example· 15

Configuring traffic policing, GTS, and rate limit 19

Overview·· 19

Traffic evaluation and token buckets· 19

Traffic policing· 20

GTS· 21

Rate limit 22

Configuring traffic policing· 23

Configuring GTS· 24

Configuring the rate limit 24

Displaying and maintaining traffic policing, GTS, and rate limit 25

Traffic policing, GTS, and rate limit configuration example· 25

Traffic policing configuration example· 25

Configuring congestion management 28

Overview·· 28

SP queuing· 28

WRR queuing· 29

WFQ queuing· 30

SP+WRR queuing· 30

SP+WFQ queuing· 30

Congestion management configuration task list 31

Configuring congestion management on a per-port basis· 31

Configuring SP queuing· 31

Configuring WRR queuing· 32

Configuring WFQ queuing· 32

Configuring SP+WRR queuing· 33

Configuring SP+WFQ queuing· 34

Displaying and maintaining congestion management 35

Configuring a queue scheduling profile· 36

Configuration procedure· 36

Displaying and maintaining queue scheduling profiles· 37

Queue scheduling profile configuration example· 38

Configuring traffic filtering· 39

Configuration procedure· 39

Configuration example· 40

Network requirements· 40

Configuration procedure· 40

Configuring priority marking· 41

Overview·· 41

Configuration procedure· 41

Support for priority marking actions· 42

Priority marking configuration examples· 42

Local precedence marking configuration example· 42

Local QoS ID marking configuration example· 44

Configuring traffic redirecting· 48

Configuration procedure· 48

Configuration example· 49

Network requirements· 49

Configuration procedure· 49

Configuring aggregate CAR· 51

Configuration procedure· 51

Displaying and maintaining aggregate CAR·· 52

Aggregate CAR configuration example· 52

Network requirements· 52

Configuration procedure· 53

Configuring class-based accounting· 54

Configuration procedure· 54

Configuration example· 55

Network requirements· 55

Configuration procedure· 55

Configuring queue-based accounting· 57

Configuration procedure· 57

Displaying and maintaining queue-based accounting· 57

Appendixes· 58

Appendix A Default priority maps· 58

Appendix B Introduction to packet precedence· 59

IP precedence and DSCP values· 59

802.1p priority· 60

 


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.

Network resources are limited. When configuring a QoS scheme, you must consider the characteristics of different applications. For example, when bandwidth is fixed, more bandwidth used by one user leaves less bandwidth for others. QoS prioritizes traffic to balance the interests of users and manages network 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. As the simplest 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.

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, but not 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 overview

The QoS techniques include traffic classification, traffic policing, traffic shaping, rate limit, congestion management, and 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 certain 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 shapingAdapts 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.

 


Configuring a QoS policy

You can configure QoS by using the MQC approach or non-MQC approach. Some features support both approaches, but some support only one.

Non-MQC approach

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.

MQC approach

In the modular QoS configuration (MQC) approach, you configure QoS service parameters by using QoS policies. A QoS policy defines the shaping, policing, or other QoS actions to take on different classes of traffic. It is a set of class-behavior associations.

A traffic class is a set of match criteria for identifying traffic, and it uses the AND or OR operator:

·          If the operator is AND, a packet must match all the criteria to match the traffic class.

·          If the operator is OR, a packet matches the traffic class if it matches any of the criteria in the traffic class.

A traffic behavior defines a set of QoS actions to take on packets, such as priority marking and redirect.

By associating a traffic behavior with a traffic class in a QoS policy, you apply the specific set of QoS actions to the traffic class.

Configuration procedure diagram

Figure 2 shows how to configure a QoS policy.

Figure 2 QoS policy configuration procedure

 

Defining a traffic class

Configuration restrictions and guidelines

When you configure a traffic class, follow these restrictions and guidelines:

·          To configure multiple values for a match criterion, perform the following tasks:

a.    Set the logical operator to OR.

b.    Configure multiple if-match commands for the match criterion.

For the service-vlan-id match criterion, you can configure multiple values in one if-match command when the logical operator is OR or AND.

·          If the configured logical operator is AND for the traffic class, the actual logical operator for the rules in an ACL match criterion is OR.

Configuration procedure

To define a traffic class:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

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

By default, no traffic class is configured.

3.       Configure match criteria.

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.

 

Table 1 Available match criteria

Option

Description

acl [ ipv6 ] { acl-number | name acl-name }

Matches an ACL.

The acl-number argument has the following value ranges:

·         2000 to 3999 for IPv4 and IPv6 ACLs.

·         4000 to 4999 for Layer 2 ACLs.

·         5000 to 5999 for user-defined ACLs.

The acl-name argument is a case-insensitive string of 1 to 63 characters, which must start with an English letter. To avoid confusion, make sure the argument is not all.

any

Matches all packets.

customer-dot1p dot1p-value&<1-8>

Matches 802.1p priority values in inner VLAN tags of double-tagged packets.

The dot1p-value&<1-8> argument specifies a space-separated list of up to eight 802.1p priority values. The value range for the dot1p-value argument is 0 to 7.

 

destination-mac mac-address

Matches a destination MAC address.

dscp dscp-value&<1-8>

Matches DSCP values.

The dscp-value&<1-8> argument specifies a space-separated list of up to eight DSCP values. The value range for the dscp-value argument is 0 to 63 or keywords shown in Table 2.

ip-precedence ip-precedence-value&<1-8>

Matches IP precedence.

The ip-precedence-value&<1-8> argument specifies a space-separated list of up to eight IP precedence values. The value range for the ip-precedence-value argument is 0 to 7.

protocol protocol-name

Matches a protocol.

The protocol-name argument can only be IP.

qos-local-id local-id-value

Matches a local QoS ID in the range of 1 to 4095.

 

service-dot1p dot1p-value&<1-8>

Matches 802.1p priority values in outer VLAN tags.

The dot1p-value&<1-8> argument specifies a space-separated list of up to eight 802.1p priority values. The value range for the dot1p-value argument is 0 to 7.

service-vlan-id vlan-id-list

Matches VLAN IDs in outer VLAN tags.

The vlan-id-list argument specifies a space-separated list of up to 10 VLAN items. Each item specifies a VLAN or a range of VLANs in the form of vlan-id1 to vlan-id2. The value for vlan-id2 must be equal to or greater than the value for vlan-id1. The value range for the vlan-id argument is 1 to 4094.

source-mac mac-address

Matches a source MAC address.

vxlan { any | vxlan-id }

Matches a VXLAN ID.

 

Table 2 DSCP keywords and values

Keyword

DSCP value (binary)

DSCP value (decimal)

default

000000

0

af11

001010

10

af12

001100

12

af13

001110

14

af21

010010

18

af22

010100

20

af23

010110

22

af31

011010

26

af32

011100

28

af33

011110

30

af41

100010

34

af42

100100

36

af43

100110

38

cs1

001000

8

cs2

010000

16

cs3

011000

24

cs4

100000

32

cs5

101000

40

cs6

110000

48

cs7

111000

56

ef

101110

46

 

Defining a traffic behavior

A traffic behavior is a set of QoS actions (such as traffic filtering, shaping, policing, and priority marking) to take on a traffic class.

To define a traffic behavior:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

traffic behavior behavior-name

By default, no traffic behavior is configured.

3.       Configure actions in the traffic behavior.

See the subsequent chapters, depending on the purpose of the traffic behavior: traffic policing, traffic filtering, priority marking, traffic accounting, and so on.

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

 

Defining a QoS policy

You associate a traffic behavior with a traffic class in a QoS policy to perform the actions defined in the traffic behavior for the traffic class of packets.

When an ACL is referenced by a QoS policy for traffic classification, the action (permit or deny) in the ACL is ignored, and the actions in the associated traffic behavior are performed.

To associate a traffic class with a traffic behavior in a QoS policy:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

qos policy policy-name

By default, no QoS policy is configured.

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 [ 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.

 

Applying the QoS policy

You can apply a QoS policy to the following destinations:

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

·          A 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.

You can modify traffic classes, traffic behaviors, and class-behavior associations in a QoS policy even after it is applied. If a traffic class references an ACL for traffic classification, you can delete or modify the ACL (such as add rules to, delete rules from, and modify rules of the ACL).

QoS policies applied to an interface, a VLAN, and globally are in descending order of priority. In other words, the switch first matches the criteria in the QoS policy applied to an interface. If there is a match, the switch executes the QoS policy applied to the interface and ignores the QoS policies applied to the VLAN and globally.

Applying the QoS policy to an interface

The term "interface" in this section collectively refers to Layer 2 Ethernet interfaces, Layer 3 Ethernet interfaces, Layer 3 Ethernet subinterfaces, and VSI interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN Switching Configuration Guide).

A QoS policy can be applied to multiple interfaces, but only one QoS policy can be applied in one direction (inbound or outbound) of an interface.

The QoS policy applied to the outgoing traffic on an interface does not regulate local packets, which are critical protocol packets sent by the local system for operation maintenance. The most common local packets include link maintenance, routing (IS-IS, BGP, and OSPF for example), RIP, LDP, RSVP, and SSH packets.

To apply the QoS policy to an interface:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view.

interface interface-type interface-number

N/A

3.       Apply the QoS policy to the interface.

qos apply policy policy-name { inbound | outbound }

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

The switch does not support applying a QoS policy to the outbound direction of a Layer 3 Ethernet subinterface.

 

Applying the QoS policy to a VLAN

You can apply a QoS policy to a VLAN to regulate traffic of the VLAN.

Configuration restrictions and guidelines

QoS policies cannot be applied to dynamic VLANs.

Configuration procedure

To apply the QoS policy to a VLAN:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

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

To apply the QoS policy globally:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Apply the QoS policy globally.

qos apply policy policy-name global { inbound | outbound }

By default, no QoS policy is applied globally.

 

Displaying and maintaining QoS policies

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

 

Task

Command

Display traffic class configuration (in standalone mode).

display traffic classifier user-defined [ classifier-name ] [ slot slot-number ]

Display traffic class configuration (in IRF mode).

display traffic classifier user-defined [ classifier-name ] [ chassis chassis-number slot slot-number ]

Display traffic behavior configuration (in standalone mode).

display traffic behavior user-defined [ behavior-name ] [ slot slot-number ]

Display traffic behavior configuration (in IRF mode).

display traffic behavior user-defined [ behavior-name ] [ chassis chassis-number slot slot-number ]

Display QoS and ACL resource usage (in standalone mode).

display qos-acl resource [ slot slot-number ]

Display QoS and ACL resource usage (in IRF mode).

display qos-acl resource [ chassis chassis-number slot slot-number ]

Display QoS policy configuration (in standalone mode).

display qos policy user-defined [ policy-name [ classifier classifier-name ] ] [ slot slot-number ]

Display QoS policy configuration (in IRF mode).

display qos policy user-defined [ policy-name [ classifier classifier-name ] ] [ chassis chassis-number slot slot-number ]

Display QoS policy configuration on the specified or all interfaces.

display qos policy interface [ interface-type interface-number ] [ inbound | outbound ]

Display information about QoS policies applied to VLANs (in standalone mode).

display qos vlan-policy { name policy-name | vlan vlan-id } [ slot slot-number ] [ inbound | outbound ]

Display information about QoS policies applied to VLANs (in IRF mode).

display qos vlan-policy { name policy-name | vlan [ vlan-id ] } [ chassis chassis-number slot slot-number ] [ inbound | outbound ]

Display information about QoS policies applied globally (in standalone mode).

display qos policy global [ slot slot-number ] [ inbound | outbound ]

Display information about QoS policies applied globally (in IRF mode).

display qos policy global [ chassis chassis-number slot slot-number ] [ inbound | outbound ]

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 ]

 

 


Configuring priority mapping

Overview

When a packet arrives, depending on your configuration, a device assigns a set of QoS priority parameters to the packet based on either a certain priority field carried in the packet or 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 priorities such as 802.11e priority, 802.1p priority, DSCP, IP precedence, local precedence, and drop priority.

Introduction to 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 and drop 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.

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 switch provides the following priority mapping tables:

·          dot1p-dp—802.1p-to-drop priority mapping table.

·          dot1p-lp—802.1p-to-local priority mapping table.

·          dscp-dot1p—DSCP-to-802.1p priority mapping table, which is applicable to only IP packets.

·          dscp-dp—DSCP-to-drop priority mapping table, which is applicable to only IP packets.

·          dscp-dscp—DSCP-to-DSCP priority mapping table, which is applicable to only IP packets that are forwarded at Layer 3 by the local switch.

The default priority maps (as shown in "Appendix A 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 trust mode on a port

The priority trust mode on a port determines which priority is used for priority mapping table lookup. Port priority was introduced to use for priority mapping in addition to the priority fields carried in packets. The Switch Series provides the following priority trust modes:

·          Using the 802.1p priority carried in packets for priority mapping.

Table 3 Priority mapping results of trusting the 802.1p priority (when the default dot1p-lp priority mapping table is used)

802.1p priority carried in packets

Local precedence

Queue ID

0

2

2

1

0

0

2

1

1

3

3

3

4

4

4

5

5

5

6

6

6

7

7

7

 

 

NOTE:

When the 802.1p priority carried in packets is trusted, the port priority is used for priority mapping for packets which do not carry VLAN tags (namely, do not carry 802.1p priorities.) The priority mapping results are the same as not trusting packet priority, as shown in Table 3.

 

·          Using the DSCP carried in packets for priority mapping.

Table 4 Priority mapping results of trusting the DSCP (when the default dscp-dot1p and dot1p-lp priority mapping tables are used)

DSCP value carried in packets

Local precedence

Queue ID

0 to 7

2

2

8 to 15

0

0

16 to 23

1

1

24 to 31

3

3

32 to 39

4

4

40 to 47

5

5

48 to 55

6

6

56 to 63

7

7

 

The priority mapping procedure varies with the priority trust modes. For more information, see the subsequent section.

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 process 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

 

Priority mapping configuration tasks

You can modify priority mappings by modifying priority mapping tables, priority trust mode on a port, and port priority.

To configure priority mapping, perform the following tasks:

 

Tasks at a glance

(Optional.) Configuring a priority map

(Required.) Perform one of the following tasks:

·         Configuring a port to trust packet priority for priority mapping

·         Changing the port priority of an interface

 

Configuring a priority map

The term "interface" in this section collectively refers to Layer 2 and Layer 3 Ethernet interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN Switching Configuration Guide).

To configure priority maps:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter priority map view.

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

N/A

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 "Appendix A Default priority maps."

Newly configured mappings overwrite the old ones.

 

Configuring a port to trust packet priority for priority mapping

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

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

·          dot1pUses the 802.1p priority of received packets for mapping.

·          dscpUses the DSCP precedence of received IP packets for mapping.

To configure the trusted packet priority type on an interface:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view.

interface interface-type interface-number

N/A

3.       Configure the trusted packet priority type.

·         Configure the interface to trust the DSCP precedence.
qos trust dscp

·         Configure the interface to trust the 802.1p priority of received packets.
undo qos trust

Use one of these commands.

By default, the interface trusts the 802.1p priority.

 

Changing the port priority of an interface

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

To change the port priority of an interface:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view.

interface interface-type interface-number

N/A

3.       Set the port priority of the interface.

qos priority priority-value

The default setting is 0.

 

Displaying and maintaining priority mapping

Execute display commands in any view.

 

Task

Command

Display priority map configuration.

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

Display the trusted packet priority type on a port.

display qos trust interface [ interface-type interface-number ]

 

Priority mapping configuration examples

Priority trust mode configuration example

Network requirements

As shown in Figure 4, Device A is connected to FortyGigE 1/0/1 of Device C, Device B is connected to FortyGigE 1/0/2 of Device C, and the packets from Device A and Device B to Device C are not VLAN tagged.

Configure Device C to preferentially process packets from Device A to Server when FortyGigE 1/0/3 of Device C is congested.

Figure 4 Network diagram

 

Configuration procedure

# Assign port priority to FortyGigE 1/0/1 and FortyGigE 1/0/2. Make sure that the priority of FortyGigE 1/0/1 is higher than that of FortyGigE 1/0/2, and that no trusted packet priority type is configured on FortyGigE 1/0/1 or FortyGigE 1/0/2.

<DeviceC> system-view

[DeviceC] interface FortyGigE 1/0/1

[DeviceC-FortyGigE1/0/1] qos priority 3

[DeviceC-FortyGigE1/0/1] quit

[DeviceC] interface FortyGigE 1/0/2

[DeviceC-FortyGigE1/0/2] qos priority 1

[DeviceC-FortyGigE1/0/2] quit

Priority mapping table and priority marking configuration example

Network requirements

As shown in Figure 5:

·          The marketing department connects to FortyGigE1/0/1 of Device, which sets the 802.1p priority of traffic from the marketing department to 3.

·          The R&D department connects to FortyGigE1/0/2 of Device, which sets the 802.1p priority of traffic from the R&D department to 4.

·          The management department connects to FortyGigE1/0/3 of Device, which sets the 802.1p priority of traffic from the management department to 5.

Configure port priority, 802.1p-to-local mapping table, and priority marking to implement the plan as described in Table 5.

Table 5 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

4

Medium

 

Figure 5 Network diagram

 

Configuration procedure

1.        Enable trusting port priority:

# Set the port priority of FortyGigE 1/0/1 to 3.

<Device> system-view

[Device] interface FortyGigE 1/0/1

[Device-FortyGigE1/0/1] qos priority 3

[Device-FortyGigE1/0/1] quit

# Set the port priority of FortyGigE 1/0/2 to 4.

[Device] interface FortyGigE 1/0/2

[Device-FortyGigE1/0/2] qos priority 4

[Device-FortyGigE1/0/2] quit

# Set the port priority of FortyGigE 1/0/3 to 5.

[Device] interface FortyGigE 1/0/3

[Device-FortyGigE1/0/3] qos priority 5

[Device-FortyGigE1/0/3] quit

2.        Configure the 802.1p-to-local mapping table to map 802.1p priority values 3, 4, and 5 to local precedence values 2, 6, and 4. This guarantees the R&D department, management department, and marketing department decreased priorities to access the public server.

[Device] qos map-table dot1p-lp

[Device-maptbl-dot1p-lp] import 3 export 2

[Device-maptbl-dot1p-lp] import 4 export 6

[Device-maptbl-dot1p-lp] import 5 export 4

[Device-maptbl-dot1p-lp] quit

3.        Configure priority marking:

# Create ACL 3000 to match HTTP traffic.

[Device] acl number 3000

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

[Device-acl-adv-3000] quit

# Create class http and reference ACL 3000 in the class.

[Device] traffic classifier http

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

[Device-classifier-http] quit

# Configure a priority marking policy for the management department, and apply the policy to the incoming traffic of FortyGigE 1/0/3.

[Device] traffic behavior admin

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

[Device-behavior-admin] quit

[Device] qos policy admin

[Device-qospolicy-admin] classifier http behavior admin

[Device-qospolicy-admin] quit

[Device] interface FortyGigE 1/0/3

[Device-FortyGigE1/0/3] qos apply policy admin inbound

# Configure a priority marking policy for the marketing department, and apply the policy to the incoming traffic of FortyGigE 1/0/1.

[Device] traffic behavior market

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

[Device-behavior-market] quit

[Device] qos policy market

[Device-qospolicy-market] classifier http behavior market

[Device-qospolicy-market] quit

[Device] interface FortyGigE 1/0/1

[Device-FortyGigE1/0/1] qos apply policy market inbound

# Configure a priority marking policy for the R&D department, and apply the policy to the incoming traffic of FortyGigE 1/0/2.

[Device] traffic behavior rd

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

[Device-behavior-rd] quit

[Device] qos policy rd

[Device-qospolicy-rd] classifier http behavior rd

[Device-qospolicy-rd] quit

[Device] interface FortyGigE 1/0/2

[Device-FortyGigE1/0/2] qos apply policy rd inbound

 


Configuring traffic policing, GTS, and rate limit

Overview

Traffic policing 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, and is called "conforming traffic." Otherwise, the traffic does not conform to the specification, and is 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. In each evaluation, if the number of tokens in the bucket is enough, the traffic conforms to the specification and the tokens for forwarding the packet are taken away. If the number of tokens in the bucket is not enough, the traffic is excessive.

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. For example, traffic policing can use the following mechanisms:

·          Single rate two colorUses 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 colorUses 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. The EBS 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 enough tokens, the packet is colored red.

·          Two rate three colorUses 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 enough tokens, the packet is colored red.

Traffic policing

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

Figure 6 Traffic policing

 

Traffic policing is widely used in policing traffic entering the networks of ISPs. It can classify the policed traffic and take pre-defined 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."

The switch forwards green and yellow packets and drops red packets.

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 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 switch supports rate limiting only outbound traffic.

The rate limit of a physical interface specifies the maximum rate for forwarding packets (including 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 physical 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 a physical interface. It is easier to use than traffic policing in controlling the total traffic rate on a physical interface.

Configuring traffic policing

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

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

By default, no traffic class is configured.

3.       Configure match criteria.

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.

4.       Return to system view.

quit

N/A

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

traffic behavior behavior-name

By default, no traffic behavior is configured.

6.       Configure a traffic policing action.

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

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

Use either of the commands.

By default, no traffic policing action is configured.

7.       Return to system view.

quit

N/A

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

qos policy policy-name

By default, no QoS policy is configured.

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

classifier classifier-name behavior behavior-name [ insert-before before-classifier-name ]

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

10.     Return to system view.

quit

N/A

11.     Apply the QoS policy.

·         Applying the QoS policy to an interface

·         Applying the QoS policy to a VLAN

·         Applying the QoS policy globally

Choose one of the application destinations as needed.

By default, no QoS policy is applied.

A traffic policing action takes effect only if you apply the QoS policy to the inbound direction.

12.     (Optional.) Display traffic policing configuration.

display traffic behavior user-defined [ behavior-name ]

Available in any view.

 

Configuring GTS

The term "interface" in this section collectively refers to Layer 2 and Layer 3 Ethernet interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN Switching Configuration Guide).

The switch supports configuring queue-based GTS. In queue-based GTS, you set GTS parameters for packets of a certain queue.

To configure GTS:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view.

interface interface-type interface-number

N/A

3.       Configure GTS for a queue.

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

By default, GTS is not configured on an interface.

 

Configuring the rate limit

The term "interface" in this section collectively refers to Layer 2 and Layer 3 Ethernet interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN Switching Configuration Guide).

The rate limit of a physical interface specifies the maximum rate of outgoing packets.

To configure the rate limit:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view.

interface interface-type interface-number

N/A

3.       Configure the rate limit for the interface.

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

By default, rate limit is not configured on an interface.

 

Displaying and maintaining traffic policing, GTS, and rate limit

Execute display commands in any view.

 

Task

Command

Display QoS and ACL resource usage (in standalone mode).

display qos-acl resource [ slot slot-number ]

Display QoS and ACL resource usage (in IRF mode).

display qos-acl resource [ chassis chassis-number slot slot-number ]

Display traffic behavior configuration.

display traffic behavior user-defined [ behavior-name ]

Display GTS configuration and statistics on an interface.

display qos gts interface [ interface-type interface-number ]

Display rate limit configuration and statistics on an interface.

display qos lr interface [ interface-type interface-number ]

 

Traffic policing, GTS, and rate limit configuration example

Traffic policing configuration example

Network requirements

As shown in Figure 10, the server, Host A, and Host B can access the Internet through Device A and Device B.

Perform traffic control on FortyGigE 1/0/1 of Device A for incoming traffic from the server and Host A to meet the following requirements:

·          Limit the rate of traffic from the server to 102400 kbps: Forward the conforming traffic, and drop the excess traffic.

·          Limit the rate of traffic from Host A to 25600 kbps: Forward the conforming traffic, and drop the excess traffic.

Figure 10 Network diagram

 

Configuration procedure

# Configure ACL 2001 and ACL 2002 to match traffic from Server and Host A, respectively.

<DeviceA> system-view

[DeviceA] acl number 2001

[DeviceA-acl-basic-2001] rule permit source 1.1.1.1 0

[DeviceA-acl-basic-2001] quit

[DeviceA] acl number 2002

[DeviceA-acl-basic-2002] rule permit source 1.1.1.2 0

[DeviceA-acl-basic-2002] quit

# Create a class named server and use ACL 2001 as the match criterion. Create a class named host and use ACL 2002 as the match criterion.

[DeviceA] traffic classifier server

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

[DeviceA-classifier-server] quit

[DeviceA] traffic classifier host

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

[DeviceA-classifier-host] quit

# Create a behavior named server and configure the CAR action (102400 kbps CIR) for the behavior.

[DeviceA] traffic behavior server

[DeviceA-behavior-server] car cir 102400

[DeviceA-behavior-server] quit

# Create a behavior named host and configure the CAR action (25600 kbps CIR) for the behavior.

[DeviceA] traffic behavior host

[DeviceA-behavior-host] car cir 25600

[DeviceA-behavior-host] quit

# Create a QoS policy named car and associate class server with behavior server and class host with behavior host.

[DeviceA] qos policy car

[DeviceA-qospolicy-car] classifier server behavior server

[DeviceA-qospolicy-car] classifier host behavior host

[DeviceA-qospolicy-car] quit

# Apply QoS policy car to the incoming traffic of port FortyGigE 1/0/1.

[DeviceA] interface FortyGigE 1/0/1

[DeviceA-FortyGigE1/0/1] qos apply policy car inbound

 


Configuring congestion management

Overview

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 11 shows two typical congestion scenarios.

Figure 11 Traffic congestion scenarios

 

Congestion brings 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 multi-user 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 uses queuing and scheduling algorithms to classify and sort traffic leaving a port.

Queue scheduling prioritizes packets to transmit high-priority packets preferentially. The switch supports Strict Priority (SP) queuing, Weighted Round Robin (WRR) queuing, Weighted Fair Queuing (WFQ), SP+WRR queuing, and SP+WFQ queuing.

SP queuing

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

Figure 12 SP queuing

 

In Figure 12, 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, and common service packets to the low priority queues to be transmitted when the 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 every queue is served for a certain time, as shown in Figure 13.

Figure 13 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) to decide the proportion of resources assigned to the queue. On a 10 Gbps port, you can configure the weight values of WRR queuing to 5, 5, 3, 3, 1, 1, 1, and 1 (corresponding to w7, w6, w5, w4, w3, w2, w1, and w0, respectively). In this way, the queue with the lowest priority can get a minimum of 500 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 maximizes bandwidth usage.

WFQ queuing

Figure 14 WFQ queuing

 

WFQ is similar to WRR. The difference is that WFQ enables you to set guaranteed bandwidth that a WFQ queue can get during congestion.

SP+WRR queuing

You can implement SP+WRR queuing by configuring some queues on an interface to use SP queuing and others to use WRR queuing.

With this SP+WRR queuing method, the system schedules queues in the following order:

1.        Schedules the queues in the SP group.

2.        Schedules queues in the WRR group when all queues in the SP group are empty.

The queues in the SP group are scheduled based on their priorities. The queues in the WRR group are scheduled based on their weights.

SP+WFQ queuing

You can configure SP+WFQ queuing as follows:

·          Assign some queues to the SP group.

·          Assign others to the WFQ group.

Congestion management configuration task list

To configure hardware congestion management, you can use one of the following methods:

·          Configure queue scheduling for each queue in interface view.

·          Configure a queue scheduling profile, as described in "Configuring a queue scheduling profile."

 

Tasks at a glance

 

Perform one of the following tasks to configure congestion management on a per-port basis:

·         Configuring SP queuing

·         Configuring WRR queuing

·         Configuring WFQ queuing

·         Configuring SP+WRR queuing

·         Configuring SP+WFQ queuing

Configuring a queue scheduling profile

 

Configuring congestion management on a per-port basis

The term "interface" in this section collectively refers to Layer 2 and Layer 3 Ethernet interfaces. You can use the port link-mode command to configure an Ethernet port as a Layer 2 or Layer 3 interface (see Layer 2—LAN Switching Configuration Guide).

Configuring SP queuing

Configuration procedure

To configure SP queuing:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view.

interface interface-type interface-number

N/A

3.       (Optional.) Configure SP queuing.

qos sp

The default queuing algorithm on an interface is SP queuing.  

 

Configuration example

Configure FortyGigE 1/0/1 to use SP queuing:

# Enter system view

<Sysname> system-view

# Configure FortyGigE 1/0/1 to use SP queuing.

[Sysname] interface FortyGigE 1/0/1

[Sysname-FortyGigE1/0/1] qos sp

Configuring WRR queuing

Configuration procedure

To configure WRR queuing:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view.

interface interface-type interface-number

N/A

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

qos wrr { byte-count | weight }

The default queuing algorithm on an interface is byte-count 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

Select weight or byte-count according to the WRR type (byte-count or packet-based) you have enabled.

By default, the weights of queues 0 through 7 are 1, 2, 3, 4, 5, 6, 7, and 8, respectively.

 

Configuration example

1.        Network requirements

Enable packet-based WRR on FortyGigE 1/0/1. Configure the weights of queues 0 through 7 as 1, 2, 4, 6, 1, 2, 4, and 6, respectively.

2.        Configuration procedure

# Enter system view.

<Sysname> system-view

# Configure WRR queuing on FortyGigE 1/0/1.

[Sysname] interface FortyGigE 1/0/1

[Sysname-FortyGigE1/0/1] qos wrr weight

[Sysname-FortyGigE1/0/1] qos wrr 0 group 1 weight 1

[Sysname-FortyGigE1/0/1] qos wrr 1 group 1 weight 2

[Sysname-FortyGigE1/0/1] qos wrr 2 group 1 weight 4

[Sysname-FortyGigE1/0/1] qos wrr 3 group 1 weight 6

[Sysname-FortyGigE1/0/1] qos wrr 4 group 1 weight 1

[Sysname-FortyGigE1/0/1] qos wrr 5 group 1 weight 2

[Sysname-FortyGigE1/0/1] qos wrr 6 group 1 weight 4

[Sysname-FortyGigE1/0/1] qos wrr 7 group 1 weight 6

Configuring WFQ queuing

Configuration procedure

To configure WFQ queuing:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view.

interface interface-type interface-number

N/A

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

qos wfq { byte-count | weight }

The default queuing algorithm on an interface is 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

Select weight or byte-count according to the WFQ type (byte-count or packet-based) you have enabled.

By default, all queues have a weight of 1.

5.       (Optional.) Configure the minimum guaranteed bandwidth for a WFQ queue.

qos bandwidth queue queue-id min bandwidth-value

The default setting is 64 kbps for each queue.

 

Configuration example

1.        Network requirements

Configure WFQ queuing as follows:

¡  Configure byte-count WFQ queuing on interface FortyGigE 1/0/1.

¡  Configure the weights of queues 0 through 7 as 2, 5, 10, 10, 10, 1, 2, and 4, respectively.

¡  Configure the minimum guaranteed bandwidth as 100 Mbps for each queue.

2.        Configuration procedure

# Enter system view.

<Sysname> system-view

# Configure byte-count WFQ queuing on interface FortyGigE 1/0/1.

[Sysname] interface FortyGigE 1/0/1

[Sysname-FortyGigE1/0/1] qos wfq byte-count

[Sysname-FortyGigE1/0/1] qos wfq 1 group 1 byte-count 2

[Sysname-FortyGigE1/0/1] qos wfq 3 group 1 byte-count 5

[Sysname-FortyGigE1/0/1] qos wfq 4 group 1 byte-count 10

[Sysname-FortyGigE1/0/1] qos wfq 5 group 1 byte-count 10

[Sysname-FortyGigE1/0/1] qos wfq 6 group 1 byte-count 10

[Sysname-FortyGigE1/0/1] qos wfq 0 group 1 byte-count 1

[Sysname-FortyGigE1/0/1] qos wfq 2 group 1 byte-count 2

[Sysname-FortyGigE1/0/1] qos wfq 7 group 1 byte-count 4

[Sysname-FortyGigE1/0/1] qos bandwidth queue 0 min 100000

[Sysname-FortyGigE1/0/1] qos bandwidth queue 1 min 100000

[Sysname-FortyGigE1/0/1] qos bandwidth queue 2 min 100000

[Sysname-FortyGigE1/0/1] qos bandwidth queue 3 min 100000

[Sysname-FortyGigE1/0/1] qos bandwidth queue 4 min 100000

[Sysname-FortyGigE1/0/1] qos bandwidth queue 5 min 100000

[Sysname-FortyGigE1/0/1] qos bandwidth queue 6 min 100000

[Sysname-FortyGigE1/0/1] qos bandwidth queue 7 min 100000

Configuring SP+WRR queuing

Configuration procedure

To configure SP+WRR queuing:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view or port group view.

interface interface-type interface-number

N/A

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

qos wrr { byte-count | weight }

The default queuing algorithm on an interface is SP queuing.

4.       Assign a queue to the SP queue scheduling group.

qos wrr queue-id group sp

By default, all the queues of a WRR-enabled port are in WRR group 1.

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

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

Select weight or byte-count according to the WRR type (byte-count or packet-based) you have enabled.

By default, the weights of queues 0 through 7 are 1, 2, 3, 4, 5, 6, 7, and 8, respectively.

 

Configuration example

1.        Network requirements

Configure SP+WRR queuing as follows:

¡  Configure SP+WRR queuing on FortyGigE 1/0/1, and use byte-count WRR.

¡  Assign queues 0, 1, 2, and 3 on FortyGigE 1/0/1 to the SP group.

¡  Assign queues 4, 5, 6, and 7 on FortyGigE 1/0/1 to the WRR group, with the weights being 1, 2, 1, and 3, respectively.

2.        Configuration procedure

# Enter system view.

<Sysname> system-view

# Configure SP+WRR queuing on FortyGigE1/0/1.

[Sysname] interface FortyGigE 1/0/1

[Sysname-FortyGigE1/0/1] qos wrr byte-count

[Sysname-FortyGigE1/0/1] qos wrr 0 group sp

[Sysname-FortyGigE1/0/1] qos wrr 1 group sp

[Sysname-FortyGigE1/0/1] qos wrr 2 group sp

[Sysname-FortyGigE1/0/1] qos wrr 3 group sp

[Sysname-FortyGigE1/0/1] qos wrr 4 group 1 byte-count 1

[Sysname-FortyGigE1/0/1] qos wrr 5 group 1 byte-count 2

[Sysname-FortyGigE1/0/1] qos wrr 6 group 1 byte-count 1

[Sysname-FortyGigE1/0/1] qos wrr 7 group 1 byte-count 3

Configuring SP+WFQ queuing

Configuration procedure

To configure SP+WFQ queuing:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

2.       Enter interface view or port group view.

interface interface-type interface-number

N/A

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

qos wfq { byte-count | weight }

The default queuing algorithm on an interface is SP queuing.

4.       Assign a queue to the SP queue scheduling group.

qos wfq queue-id group sp

By default, all the queues of a WFQ-enabled port are in WFQ group 1.

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

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

Select weight or byte-count according to the WFQ type (byte-count or packet-based) you have enabled.

By default, all queues have a weight of 1.

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

qos bandwidth queue queue-id min bandwidth-value

The default setting is 64 kbps for each queue in a WFQ group.

 

Configuration example

1.        Network requirements

Configure SP+WFQ queuing as follows:

¡  Configure SP+WFQ queuing on interface FortyGigE 1/0/1, and use packet-based WFQ.

¡  Assign queues 0, 1, 2, and 3 to the SP group.

¡  Assign queues 4, 5, 6, and 7 to the WFQ group, with the weights being 1, 2, 1, and 3, respectively.

2.        Configuration procedure

# Enter system view.

<Sysname> system-view

# Configure SP+WFQ queuing on FortyGigE 1/0/1.

[Sysname] interface FortyGigE 1/0/1

[Sysname-FortyGigE1/0/1] qos wfq weight

[Sysname-FortyGigE1/0/1] qos wfq 0 group sp

[Sysname-FortyGigE1/0/1] qos wfq 1 group sp

[Sysname-FortyGigE1/0/1] qos wfq 2 group sp

[Sysname-FortyGigE1/0/1] qos wfq 3 group sp

[Sysname-FortyGigE1/0/1] qos wfq 4 group 1 weight 1

[Sysname-FortyGigE1/0/1] qos bandwidth queue 4 min 128000

[Sysname-FortyGigE1/0/1] qos wfq 5 group 1 weight 2

[Sysname-FortyGigE1/0/1] qos bandwidth queue 5 min 128000

[Sysname-FortyGigE1/0/1] qos wfq 6 group 1 weight 1

[Sysname-FortyGigE1/0/1] qos bandwidth queue 6 min 128000

[Sysname-FortyGigE1/0/1] qos wfq 7 group 1 weight 3

 [Sysname-FortyGigE1/0/1] qos bandwidth queue 7 min 128000

Displaying and maintaining congestion management

Execute display commands in any view.

 

Task

Command

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 ]

 

Configuring a queue scheduling profile

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. When SP+WRR or SP+WFQ is configured, the scheduling priority is as follows:

·          The SP group has higher priority than WRR groups and WFQ groups.

·          Queues in the SP group are scheduled in descending order of queue IDs.

·          When queues in the SP group are empty, queues in the WRR or WFQ group are scheduled based on their weights.

When SP and WRR groups are configured in a queue scheduling profile, Figure 15 shows the scheduling order.

Figure 15 Queue scheduling profile configured with both SP and WRR

 

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

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

·          Queue 0 has the third highest priority. Packets in queue 0 are sent when queue 7 and queue 6 are both empty.

·          When queue 7, queue 6, and queue 0 are all empty, WRR group 1 is scheduled. Queue 1 through queue 5 in WRR group 1 are scheduled according to their weights.

Configuration procedure

To configure a queue scheduling profile, create the queue scheduling profile first, and then enter the queue scheduling profile view to configure its queue scheduling parameters. At last, apply the queue scheduling profile to the specified interface.

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

·          Only one queue scheduling profile can be applied to an interface.

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

To configure a queue scheduling profile:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

qos qmprofile profile-name

By default, no queue scheduling profile exists.

3.       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 1 { byte-count | weight } schedule-value

·         Configure a queue to use WFQ:

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

b.    bandwidth queue queue-id min bandwidth-value

By default, a queue scheduling profile uses SP queuing for all queues.

You can configure the same queue scheduling algorithm, SP+WRR, or SP+WFQ for all queues. However, you cannot configure WRR+WFQ for queues.

In a queue scheduling profile, you can configure different queue scheduling algorithms for different queues.

You can configure the minimum guaranteed bandwidth for only WFQ queues.

4.       Return to system view.

quit

N/A

5.       Enter interface view.

interface interface-type interface-number

N/A

6.       Apply the queue scheduling profile to the interface.

qos apply qmprofile profile-name

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

 

Displaying and maintaining queue scheduling profiles

Execute display commands in any view.

 

Task

Command

Display the configuration of the specified or all queue scheduling profiles (in standalone mode).

display qos qmprofile configuration [ profile-name ] [ slot slot-number ]

Display the configuration of the specified or all queue scheduling profiles (in IRF mode).

display qos qmprofile configuration [ profile-name ] [ chassis chassis-number slot slot-number ]

Display the queue scheduling profiles already applied to interfaces.

display qos qmprofile interface [ interface-type interface-number ]

 

Queue scheduling profile configuration example

Network requirements

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

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

·          Queues 0 through queue 6 in the WRR group are scheduled according to their weights, which are 1, 2, 4, 6, 8, 10, and 12, respectively.

Configuration procedure

# Enter system view.

<Sysname> system-view

# Create queue scheduling profile qm1.

[Sysname] qos qmprofile qm1

[Sysname-qmprofile-qm1]

# Configure queue 7 to use SP queuing.

[Sysname-qmprofile-qm1] queue 7 sp

# Assign queue 0 through queue 6 to the WRR group, with their weights as 1, 2, 4, 6, 8, 10, and 12, respectively.

[Sysname-qmprofile-qm1] queue 0 wrr group 1 weight 1

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

[Sysname-qmprofile-qm1] queue 2 wrr group 1 weight 4

[Sysname-qmprofile-qm1] queue 3 wrr group 1 weight 6

[Sysname-qmprofile-qm1] queue 4 wrr group 1 weight 8

[Sysname-qmprofile-qm1] queue 5 wrr group 1 weight 10

[Sysname-qmprofile-qm1] queue 6 wrr group 1 weight 12

[Sysname-qmprofile-qm1] quit

# Apply queue scheduling profile qm1 to interface FortyGigE 1/0/1.

[Sysname] interface FortyGigE 1/0/1

[Sysname-FortyGigE1/0/1] qos apply qmprofile qm1

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

 


Configuring 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 a specific IP address according to network status.

Configuration procedure

To configure traffic filtering:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

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

By default, no traffic class is configured.

3.       Configure match criteria.

if-match match-criteria

By default, no match criterion is configured.

4.       Return to system view.

quit

N/A

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

traffic behavior behavior-name

By default, no traffic behavior is configured.

6.       Configure the traffic filtering action.

filter { deny | permit }

By default, no traffic filtering action is configured.

If a traffic behavior has the filter deny action, all the other actions except for class-based accounting in the traffic behavior do not take effect.

7.       Return to system view.

quit

N/A

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

qos policy policy-name

By default, no QoS policy is configured.

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

classifier classifier-name behavior behavior-name [ insert-before before-classifier-name ]

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

10.     Return to system view.

quit

N/A

11.     Apply the QoS policy.

·         Applying the QoS policy to an interface

·         Applying the QoS policy to a VLAN

·         Applying the QoS policy globally

Choose one of the application destinations as needed.

By default, no QoS policy is applied.

12.     (Optional.) Display the traffic filtering configuration.

display traffic behavior user-defined [ behavior-name ]

Available in any view.

 

Configuration example

Network requirements

As shown in Figure 16, configure traffic filtering to filter the packets with source port not being 21, and received on FortyGigE 1/0/1.

Figure 16 Network diagram

 

Configuration procedure

# Create advanced ACL 3000, and configure a rule to match packets whose source port number is 21.

<Device> system-view

[Device] acl number 3000

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

[Device-acl-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 the QoS policy named policy to the incoming traffic of FortyGigE 1/0/1.

[Device] interface FortyGigE 1/0/1

[Device-FortyGigE1/0/1] qos apply policy policy inbound

 


Configuring priority marking

Overview

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 a DSCP value for a traffic class of IP packets to control the forwarding of these packets.

To configure priority marking, you can associate a traffic class with a traffic behavior configured with the priority marking action to set the priority fields or flag bits of the traffic class of packets.

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

Configuration procedure

To configure priority marking:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

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

By default, no traffic class is configured.

3.       Configure match criteria.

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.

4.       Return to system view.

quit

N/A

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

traffic behavior behavior-name [ insert-before before-classifier-name ]

By default, no traffic behavior is configured.

6.       Configure a priority marking action.

·         Set the DSCP value for packets:
remark dscp dscp-value

·         Set the local precedence for packets:
remark [ green | red | yellow ] local-precedence local-precedence-value

·         Set the local QoS ID for packets:
remark qos-local-id local-id-value

Use one or more of the commands.

By default, no priority marking action is configured.

The remark local-precedence and remark qos-local-id commands apply only to incoming traffic.

7.       Return to system view.

quit

N/A

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

qos policy policy-name

By default, no QoS policy is configured.

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

classifier classifier-name behavior behavior-name [ insert-before before-classifier-name ]

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

10.     Return to system view.

quit

N/A

11.     Apply the QoS policy.

·         Applying the QoS policy to an interface

·         Applying the QoS policy to a VLAN

·         Applying the QoS policy globally

Choose one of the application destinations as needed.

By default, no QoS policy is applied.

12.     (Optional.) Display the priority marking configuration.

display traffic behavior user-defined [ behavior-name ]

Available in any view.

 

Support for priority marking actions

When a priority marking QoS policy is applied to an interface, port group, VLAN, or globally, Table 6 shows the switch support for priority marking actions in the inbound and outbound directions.

Table 6 Support for priority marking actions

Action

Inbound

Outbound

DSCP marking

Supported

Not Supported

Local precedence marking

Supported

Not supported

 

 

NOTE:

DSCP marking takes effect only on Layer 3 packets.

 

Priority marking configuration examples

Local precedence marking configuration example

Network requirements

As shown in Figure 17, 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 17 Network diagram

 

Configuration procedure

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

<Device> system-view

[Device] acl number 3000

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

[Device-acl-adv-3000] quit

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

[Device] acl number 3001

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

[Device-acl-adv-3001] quit

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

[Device] acl number 3002

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

[Device-acl-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 the QoS policy named policy_server to the incoming traffic of FortyGigE 1/0/1.

[Device] interface FortyGigE 1/0/1

[Device-FortyGigE1/0/1] qos apply policy policy_server inbound

[Device-FortyGigE1/0/1] quit

Local QoS ID marking configuration example

Local QoS ID marking allows you to mark the same local QoS ID for packets of multiple classes. Then, you can configure a new class to match the local QoS ID to group these packets into the new class. With this feature, you can perform QoS actions for the old classes separately and perform other QoS actions for the new class. In this way, you can perform multiple layers of QoS actions for the specific packets.

Network requirements

As shown in Figure 18, configure local QoS ID marking and traffic policing to meet the following requirements:

·          Limit the outgoing traffic of the Management department and the R&D department to 102400 kbps separately.

·          Limit the outgoing traffic of the Marketing department (containing two sub-departments) to 204800 kbps.

Figure 18 Network diagram

 

Configuration considerations

To limit the traffic of the Marketing department, perform the following tasks:

1.        Mark the same local QoS ID for the traffic from the two sub-departments of the Marketing department.

2.        Configure a class to match packets with the local QoS ID.

3.        Configure a traffic policing behavior for the class to limit the outgoing traffic of the two sub-departments.

Configuration procedure

1.        Limit the upstream traffic of the Management department and R&D department:

# Configure IPv4 basic ACL 2001 to match the outgoing traffic of the Management department.

<SwitchA> system-view

[SwitchA] acl number 2001

[SwitchA-acl-basic-2001] rule permit source 192.168.1.0 0.0.0.255

[SwitchA-acl-basic-2001] quit

# Configure IPv4 basic ACL 2002 to match the outgoing traffic of the R&D department.

[SwitchA] acl number 2002

[SwitchA-acl-basic-2002] rule permit source 192.168.2.0 0.0.0.255

[SwitchA-acl-basic-2002] quit

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

[SwitchA] traffic classifier admin

[SwitchA-classifier-admin] if-match acl 2001

[SwitchA-classifier-admin] quit

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

[SwitchA] traffic classifier rd

[SwitchA-classifier-rd] if-match acl 2002

[SwitchA-classifier-rd] quit

# Create a traffic behavior named car_admin_rd, and configure traffic policing to limit the traffic rate to 102400 kbps.

[SwitchA] traffic behavior car_admin_rd

[SwitchA-behavior-car_admin_rd] car cir 102400

[SwitchA-behavior-car_admin_rd] quit

# Create a QoS policy named car, and associate classes admin and rd with behavior car_admin_rd.

[SwitchA] qos policy car

[SwitchA-qospolicy-car] classifier admin behavior car_admin_rd

[SwitchA-qospolicy-car] classifier rd behavior car_admin_rd

[SwitchA-qospolicy-car] quit

2.        Limit the upstream traffic of the Marketing department:

# Configure IPv4 basic ACL 2003 to match the outgoing traffic of sub-department 1 of the Marketing department.

[SwitchA] acl number 2003

[SwitchA-acl-basic-2003] rule permit source 192.168.3.0 0.0.0.255

[SwitchA-acl-basic-2003] quit

# Configure IPv4 basic ACL 2004 to match the outgoing traffic of sub-department 2 of the Marketing department.

[SwitchA] acl number 2004

[SwitchA-acl-basic-2004] rule permit source 192.168.4.0 0.0.0.255

[SwitchA-acl-basic-2004] quit

# Configure class marketing to match the outgoing traffic of the two sub-departments of the Marketing department.

[SwitchA] traffic classifier marketing operator or

[SwitchA-classifier-marketing] if-match acl 2003

[SwitchA-classifier-marketing] if-match acl 2004

[SwitchA-classifier-marketing] quit

# Configure behavior remark_local_id to mark traffic with local QoS ID 100.

[SwitchA] traffic behavior remark_local_id

[SwitchA-behavior-remark_local_id] remark qos-local-id 100

[SwitchA-behavior-remark_local_id] quit

# Configure class marketing_car to match the outgoing traffic of the two sub-departments of the Marketing department.

[SwitchA] traffic classifier marketing_car

[SwitchA-classifier-marketing_car] if-match qos-local-id 100

[SwitchA-classifier-marketing_car] quit

# Create behavior marketing_car, and configure traffic policing to limit the traffic rate to 204800 kbps.

[SwitchA] traffic behavior marketing_car

[SwitchA-behavior-marketing_car] car cir 204800

[SwitchA-behavior-marketing_car] quit

# In QoS policy car, associate class marketing with behavior remark_local_id to mark the outgoing traffic of the Marketing department with local QoS ID 100.

[SwitchA] qos policy car

[SwitchA-qospolicy-car] classifier marketing behavior remark_local_id

# In QoS policy car, associate class marketing_car with behavior marketing_car to limit the rate of traffic with local QoS ID 100.

[SwitchA-qospolicy-car] classifier marketing_car behavior marketing_car

[SwitchA-qospolicy-car] quit

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

[SwitchA] interface FortyGigE 1/0/1

[SwitchA-FortyGigE1/0/1] qos apply policy car inbound

 


Configuring traffic redirecting

Traffic redirecting is the action of redirecting the packets matching the specific match criteria to a certain location for processing.

The following redirect actions are supported:

·          Redirecting traffic to the CPURedirects packets that require processing by the CPU to the CPU.

·          Redirecting traffic to an interfaceRedirects packets that require processing by an interface to the interface. This action applies to only Layer 2 packets, and the target interface must be a Layer 2 interface.

Configuration procedure

To configure traffic redirecting:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

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

By default, no traffic class exists.

3.       Configure match criteria.

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.

4.       Return to system view.

quit

N/A

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

traffic behavior behavior-name

By default, no traffic behavior exists.

6.       Configure a traffic redirecting action.

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

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

The actions of redirecting traffic to the CPU and redirecting traffic to an interface are mutually exclusive with each other in the same traffic behavior. The last redirecting action configured takes effect.

7.       Return to system view.

quit

N/A

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

qos policy policy-name

By default, no QoS policy exists.

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

classifier classifier-name behavior behavior-name [ insert-before before-classifier-name ]

By default, no class-behavior association is configured for a QoS policy.

10.     Return to system view.

quit

N/A

11.     Apply the QoS policy.

·         Applying the QoS policy to an interface

·         Applying the QoS policy to a VLAN

·         Applying the QoS policy globally

Choose one of the application destinations as needed.

By default, a QoS policy is not applied.

12.     (Optional.) Display traffic redirecting configuration.

display traffic behavior user-defined [ behavior-name ]

Available in any view.

 

Configuration example

Network requirements

As shown in Figure 19:

·          Device A is connected to Device B through two links. At the same time, Device A and Device B are each connected to other devices.

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

·          FortyGigE 1/0/3 of Device A and FortyGigE 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 so that:

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

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

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

Figure 19 Network diagram

 

Configuration procedure

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

<DeviceA> system-view

[DeviceA] acl number 2000

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

[DeviceA-acl-basic-2000] quit

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

[DeviceA] acl number 2001

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

[DeviceA-acl-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 FortyGigE 1/0/2.

[DeviceA] traffic behavior behavior_1

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

[DeviceA-behavior-behavior_1] quit

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

[DeviceA] traffic behavior behavior_2

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

[DeviceA-behavior-behavior_2] quit

# Create a QoS policy named policy, associate traffic class classifier_1 with traffic behavior behavior_1, and associate traffic class classifier_2 with traffic behavior behavior_2 in the QoS policy.

[DeviceA] qos policy policy

[DeviceA-qospolicy-policy] classifier classifier_1 behavior behavior_1

[DeviceA-qospolicy-policy] classifier classifier_2 behavior behavior_2

[DeviceA-qospolicy-policy] quit

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

[DeviceA] interface FortyGigE 1/0/1

[DeviceA-FortyGigE1/0/1] qos apply policy policy inbound

 


Configuring aggregate CAR

An aggregate CAR action is created globally and can be directly applied to interfaces or referenced in the traffic behaviors associated with different traffic classes to police multiple traffic flows as a whole. The total rate of the traffic flows must conform to the traffic policing specifications set in the aggregate CAR action.

Configuration procedure

To configure aggregate CAR:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

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

By default, no traffic classes exist.

3.       Configure match criteria.

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.

4.       Return to system view.

quit

N/A

5.       Configure an aggregate CAR action.

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

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

Use either of the commands.

By default, no aggregate CAR action is configured.

6.       Enter traffic behavior view.

traffic behavior behavior-name

N/A

7.       Reference the aggregate CAR in the traffic behavior.

car name car-name

By default, no aggregate CAR action is referenced.

8.       Return to system view.

quit

N/A

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

qos policy policy-name

By default, no QoS policies exist.

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

classifier classifier-name behavior behavior-name [ mode dcbx | insert-before before-classifier-name ]

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

11.     Return to system view.

quit

N/A

12.     Apply the QoS policy.

·         Applying the QoS policy to an interface

·         Applying the QoS policy to a VLAN

·         Applying the QoS policy globally

Choose one of the application destinations as needed.

By default, no QoS policy is applied.

An aggregate CAR action takes effect only if you apply the QoS policy to the inbound direction.

 

Displaying and maintaining 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 ]

 

Aggregate CAR configuration example

Network requirements

As shown in Figure 20, configure an aggregate CAR to rate-limit the traffic of VLAN 10 and VLAN 100 received on FortyGigE 1/0/1 by using these parameters: CIR is 2560 kbps, CBS is 20480 bytes.

Figure 20 Network diagram

 

Configuration procedure

# Configure an aggregate CAR according to the rate limit requirements.

<Device> system-view

[Device] qos car aggcar-1 aggregative cir 2560 cbs 20480

# Create class 1 to match traffic of VLAN 10. Create behavior 1 and reference the aggregate CAR in the behavior.

[Device] traffic classifier 1

[Device-classifier-1] if-match service-vlan-id 10

[Device-classifier-1] quit

[Device] traffic behavior 1

[Device-behavior-1] car name aggcar-1

[Device-behavior-1] quit

# Create class 2 to match traffic of VLAN 100. Create behavior 2 and reference the aggregate CAR in the behavior.

[Device] traffic classifier 2

[Device-classifier-2] if-match service-vlan-id 100

[Device-classifier-2] quit

[Device] traffic behavior 2

[Device-behavior-2] car name aggcar-1

[Device-behavior-2] quit

# Create QoS policy car, associate class 1 with behavior 1, and associate class 2 with behavior 2.

[Device] qos policy car

[Device-qospolicy-car] classifier 1 behavior 1

[Device-qospolicy-car] classifier 2 behavior 2

[Device-qospolicy-car] quit

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

[Device] interface FortyGigE 1/0/1

[Device-FortyGigE1/0/1]qos apply policy car inbound

 


Configuring 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.

Configuration procedure

To configure class-based accounting:

 

Step

Command

Remarks

1.       Enter system view.

system-view

N/A

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

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

By default, no traffic class is configured.

3.       Configure match criteria.

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.

4.       Return to system view.

quit

N/A

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

traffic behavior behavior-name

By default, no traffic behavior is configured.

6.       Configure the accounting action.

accounting  [ byte | packet ]

By default, no traffic accounting action is configured.

7.       Return to system view.

quit

N/A

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

qos policy policy-name

By default, no QoS policy is configured.

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

classifier classifier-name behavior behavior-name [ insert-before before-classifier-name ]

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

10.     Return to system view.

quit

N/A

11.     Apply the QoS policy.

·         Applying the QoS policy to an interface

·         Applying the QoS policy to a VLAN

·         Applying the QoS policy globally

Choose one of the application destinations as needed.

By default, no QoS policy is applied.

Accounting actions can be applied only to the inbound direction.

12.     Display traffic accounting configuration.

·         In standalone mode:

¡  display qos policy global [ slot slot-number ] [ inbound | outbound ]

¡  display qos policy interface [ interface-type interface-number ] [ inbound | outbound ]

¡  display qos vlan-policy { name policy-name | vlan [ vlan-id ] } [ slot slot-number ] [ inbound | outbound ]

·         In IRF mode:

¡  display qos policy global [ chassis chassis-number slot slot-number ] [ inbound | outbound ]

¡  display qos policy interface [ interface-type interface-number ] [ inbound | outbound ]

¡  display qos vlan-policy { name policy-name | vlan [ vlan-id ] } [ chassis chassis-number slot slot-number ] [ inbound | outbound ]

Available in any view.

 

Configuration example

Network requirements

As shown in Figure 21, configure class-based accounting to collect statistics for traffic sourced from 1.1.1.1/24 and received on FortyGigE 1/0/1.

Figure 21 Network diagram

 

Configuration procedure

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

<Device> system-view

[Device] acl number 2000

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

[Device-acl-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 the QoS policy named policy to the incoming traffic of FortyGigE 1/0/1.

[Device] interface fortygige 1/0/1

[Device-FortyGigE1/0/1] qos apply policy policy inbound

[Device-FortyGigE1/0/1] quit

# Display traffic statistics to verify the configuration.

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

Interface: FortyGigE1/0/1

  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

Queue-based accounting collects the following traffic statistics on a per-queue basis:

·          The total length of a queue.

·          The number of packets dropped by a queue.

·          The current length of a queue.

·          The ratio of the current length to the total length of a queue.

Configuration procedure

To configure queue-based accounting:

 

Step

Command

Description

1.       Enter system view.

system-view

N/A

2.       Set the packet statistics collection mode to queue.

statistic mode queue

The default setting is VSI.

 

Displaying and maintaining 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 ] outbound

Display the packet statistics collection mode.

display statistic mode

Clear queue-based traffic statistics for interfaces.

reset qos queue-statistics interface [ interface-type interface-number ] outbound

 

 


Appendixes

Appendix A Default priority maps

For the default dscp-dscp priority map, an input value yields a target value equal to it.

Table 7 Default dot1p-lp and dot1p-dp priority maps

Input priority value

dot1p-lp map

dot1p-dp map

dot1p

lp

dp

0

2

0

1

0

0

2

1

0

3

3

0

4

4

0

5

5

0

6

6

0

7

7

0

 

Table 8 Default dscp-dp and dscp-dot1p priority maps

Input priority value

dscp-dp map

dscp-dot1p map

dscp

dp

dot1p

0 to 7

0

0

8 to 15

0

1

16 to 23

0

2

24 to 31

0

3

32 to 39

0

4

40 to 47

0

5

48 to 55

0

6

56 to 63

0

7

 

Appendix B Introduction to packet precedence

IP precedence and DSCP values

Figure 22 ToS and DS fields

 

As shown in Figure 22, the ToS field in the IP header contains eight bits. The first three 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, where a DSCP value is represented by the first six bits (0 to 5) and is in the range 0 to 63. The remaining two 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 and applies to occasions where Layer 3 header analysis is not needed and QoS must be assured at Layer 2.

Figure 23 An Ethernet frame with an 802.1Q tag header

 

As shown in Figure 23, the four-byte 802.1Q tag header consists of the tag protocol identifier (TPID, two bytes in length) and the tag control information (TCI, two bytes in length). The value of the TPID is 0x8100. Figure 24 shows the format of the 802.1Q tag header. The Priority field in the 802.1Q tag header is called the "802.1p priority", because its use is defined in IEEE 802.1p. Table 11 shows the values for 802.1p priority.

Figure 24 802.1Q 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

 

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