H3C S9500 Series Operating instructions

Brand: H3C

Model: S9500 Series

Type: Operating instructions

H3C S9500 Series Routing Switches

Operation Manual

Hangzhou H3C Technologies Co., Ltd.

http://www.h3c.com

Manual Version: T2-081655-20080530-C-2.03

Product Version: S9500-CMW520-R2132

No part of this manual may be reproduced or transmitted in any form or by any means

without prior written consent of Hangzhou H3C Technologies Co., Ltd.

Trademarks

H3C, , Aolynk, , H

Care,

, TOP G, , IRF, NetPilot,

Neocean, NeoVTL, SecPro, SecPoint, SecEngine, SecPath, Comware, Secware,

Storware, NQA, VVG, V

G, V

G, PSPT, XGbus, N-Bus, TiGem, InnoVision and

HUASAN are trademarks of Hangzhou H3C Technologies Co., Ltd.

All other trademarks that may be mentioned in this manual are the property of their

respective owners.

Notice

The information in this document is subject to change without notice. Every effort has

been made in the preparation of this document to ensure accuracy of the contents, but

all statements, information, and recommendations in this document do not constitute

the warranty of any kind, express or implied.

To obtain the latest information, please access:

http://www.h3c.com

Technical Support

customer_service@h3c.com

http://www.h3c.com

About This Manual

Related Documentation

In addition to this manual, each H3C S9500 Series Routing Switches documentation

set includes the following:

Manual Description

H3C S9500 Series Routing Switches

Installation Manual

It introduces the installation procedure,

commissioning, maintenance and

monitoring of the S9500 series routing

switches.

H3C S9500 Series Routing Switches

Command Manual

It includes Feature List and Command

Index, Access Volume, IP Service

Volume, IP Routing Volume, IP Multicast

Volume, MPLS VPN Volume, QoS ACL

Volume, Security Volume, System

Volume, and unsupported commands.

Organization

H3C Configuration Manual is organized as follows:

Part Contents

00 Product Overview

includes Obtaining the Documentation, Product

Features, and Features.

01 Access Volume

includes Ethernet Interface Configuration, POS

Interface Configuration, GVRP Configuration, Link

Aggregation Configuration, Port Mirroring

Configuration, RPR Configuration, Ethernet OAM

Configuration MSTP Configuration, VLAN

Configuration, QinQ Configuration, BPDU Tunneling

Configuration, and Port Isolation Configuration.

02 IP Services Volume

includes ARP Configuration, DHCP Configuration,

DNS Configuration, IP Addressing Configuration, IP

Performance Configuration, UDP Helper Configuration

IPv6 Basics Configuration, Dual Stack Configuration,

Tunneling Configuration, and Adjacency Table

Configuration.

Part Contents

03 IP Routing Volume

includes IP Routing Overview, BGP Configuration,

IS-IS Configuration, OSPF Configuration, RIP

Configuration, Routing Policy Configuration, Static

Routing Configuration, IPv6 BGP Configuration, IPv6

IS-IS Configuration, IPv6 OSPFv3 Configuration, IPv6

RIPng Configuration, and IPv6 Static Routing

Configuration.

04 IP Multicast Volume

includes Multicast Overview, Multicast Routing and

Forwarding Configuration, IGMP Snooping

Configuration, IGMP Configuration, PIM Configuration,

MSDP Configuration, IPv6 Multicast Routing and

Forwarding Configuration, MLD Snooping

Configuration, MLD Configuration, IPv6 PIM

Configuration, and Multicast VLAN Configuration.

05 MPLS VPN Volume

includes MPLS Basics Configuration, MPLS TE

Configuration, VPLS Configuration, MPLS L2VPN

Configuration, MPLS L3VPN Configuration, MPLS

Hybrid Insertion Configuration, and GRE Configuration.

06 QoS ACL Volume includes QoS Configuration and ACL Configuration.

07 Security Volume

includes 802.1x Configuration, AAA RADIUS

HWTACACS Configuration, MAC Authentication

Configuration, L3+NAT Configuration, Password

Control Configuration, SSH2.0 Configuration, and

Portal Configuration.

08 System Volume

includes GR Configuration, VRRP Configuration, HA

Configuration, Device Management Configuration,

NQA Configuration, NetStream Configuration, NTP

Configuration, RMON Configuration, SNMP

Configuration, File System Management Configuration,

System Maintaining and Debugging Configuration,

Basic System Configuration, Information Center

Configuration, User Interface Configuration, MAC

Address Table Management Configuration, PoE

Configuration, and Clock Monitoring Configuration.

09 OAA Volume

includes OAP Module Configuration and ACSEI

Configuration.

10 Acronyms Offers the acronyms used in this manual.

Conventions

The manual uses the following conventions:

I. Command conventions

Convention Description

Boldface

The keywords of a command line are in Boldface.

italic

Command arguments are in italic.

[ ]

Items (keywords or arguments) in square brackets [ ] are

optional.

{ x | y | ... }

Alternative items are grouped in braces and separated by

vertical bars. One is selected.

[ x | y | ... ]

Optional alternative items are grouped in square brackets

and separated by vertical bars. One or none is selected.

{ x | y | ... } *

Alternative items are grouped in braces and separated by

vertical bars. A minimum of one or a maximum of all can be

selected.

[ x | y | ... ] *

Optional alternative items are grouped in square brackets

and separated by vertical bars. Many or none can be

selected.

&<1-n>

The argument(s) before the ampersand (&) sign can be

entered 1 to n times.

# A line starting with the # sign is comments.

II. GUI conventions

Convention Description

< >

Button names are inside angle brackets. For example, click

<OK>.

[ ]

Window names, menu items, data table and field names

are inside square brackets. For example, pop up the [New

User] window.

Multi-level menus are separated by forward slashes. For

example, [File/Create/Folder].

III. Symbols

Convention Description

Warning

Means reader be extremely careful. Improper operation

may cause bodily injury.

Caution

Means reader be careful. Improper operation may cause

data loss or damage to equipment.

 Note Means a complementary description.

Operation Manual

H3C S9500 Series Routing Switches QoS ACL Volume Organization

Manual Version

T2-081655-20080530-C-2.03

Product Version

S9500-CMW520-R2132

Organization

The QoS ACL Volume is organized as follows:

Features (operation

manual)

Description

QoS

The volume describes:

z QoS overview

z Traffic classification and traffic shaping configuration

z QoS policy configuration

z Hardware-based congestion management configuration

z Priority mapping configuration

z Congestion avoidance configuration

z Aggregation CAR configuration

z VLAN policy configuration

z Traffic mirroring configuration

z EACL configuration

z Outbound traffic accounting configuration

ACL

Access Control Lists (ACLs) are used to filter packets

passing through network devices. The volume describes:

z ACL overview and ACL types

z ACL configuration

Operation Manual – QoS

H3C S9500 Series Routing Switches Table of Contents

Table of Contents

Chapter 1 QoS Overview .............................................................................................................. 1-1

1.1 Introduction........................................................................................................................1-1

1.2 Traditional Packets Forwarding Application ......................................................................1-1

1.3 New Requirements Caused by New Applications.............................................................1-1

1.4 Congestion: Causes, Impact, and Countermeasures........................................................1-2

1.4.1 Causes....................................................................................................................1-2

1.4.2 Impact......................................................................................................................1-3

1.4.3 Countermeasure......................................................................................................1-3

1.5 Traffic Management Technologies ....................................................................................1-3

Chapter 2 Traffic Classification and Traffic Shaping Configuration........................................2-1

2.1 Traffic Classification Overview...........................................................................................2-1

2.1.1 Traffic classification.................................................................................................2-1

2.1.2 Priority.....................................................................................................................2-2

2.2 Traffic Shaping Overview...................................................................................................2-2

2.3 Traffic Evaluation and Token Bucket.................................................................................2-2

2.4 Traffic Shaping Configuration............................................................................................2-5

Chapter 3 QoS Policy Configuration...........................................................................................3-1

3.1 QoS Policy Overview.........................................................................................................3-1

3.2 QoS Policy Configuration Procedure.................................................................................3-1

3.3 Configuring QoS Policy......................................................................................................3-2

3.3.1 Configuration Prerequisites.....................................................................................3-2

3.3.2 Defining a Class......................................................................................................3-2

3.3.3 Defining a Traffic Behavior......................................................................................3-3

3.3.4 Defining a Policy......................................................................................................3-6

3.3.5 Applying a Policy.....................................................................................................3-7

3.4 Implementing QoS in an MPLS Network...........................................................................3-9

3.4.1 Mapping Dot1p to EXP in L2VPN .........................................................................3-10

3.4.2 Implementing QoS in an MPLS Network ..............................................................3-10

3.5 Displaying and Maintaining QoS Policies........................................................................3-14

Chapter 4 Hardware-based Congestion Management Configuration......................................4-1

4.1 Congestion Management Overview...................................................................................4-1

4.1.1 SP Queuing.............................................................................................................4-1

4.1.2 WRR Queuing.........................................................................................................4-2

4.2 Configuring SP Queues.....................................................................................................4-3

4.2.1 Configuration Procedure.........................................................................................4-3

4.2.2 Configuration Examples..........................................................................................4-3

4.3 Configuring Group-based WRR Queues...........................................................................4-3

Operation Manual – QoS

H3C S9500 Series Routing Switches Table of Contents

4.3.1 Configuration Procedure.........................................................................................4-4

4.3.2 Configuration Examples..........................................................................................4-4

Chapter 5 Priority Mapping .......................................................................................................... 5-1

5.1 Priority Mapping Overview.................................................................................................5-1

5.2 Configuring a Priority Mapping Table................................................................................5-2

5.2.1 Configuration Prerequisites.....................................................................................5-3

5.2.2 Configuration Procedure.........................................................................................5-3

5.2.3 Configuration Examples..........................................................................................5-4

5.3 Configuring Port Priority.....................................................................................................5-5

5.3.1 Configuration Prerequisites.....................................................................................5-5

5.3.2 Configuration Procedure.........................................................................................5-6

5.3.3 Configuration Examples..........................................................................................5-6

5.4 Configuring to Trust Packet Priority...................................................................................5-7

5.4.1 Configuration Procedure.........................................................................................5-8

5.4.2 Configuration Examples..........................................................................................5-8

Chapter 6 Congestion Avoidance................................................................................................6-1

6.1 Congestion Avoidance Overview.......................................................................................6-1

6.2 Configuring WRED ............................................................................................................6-3

6.2.1 Description on WRED Parameters..........................................................................6-3

6.2.2 Configuration Procedure.........................................................................................6-4

6.3 Displaying and Maintaining WRED....................................................................................6-5

6.4 WRED Configuration Examples.........................................................................................6-5

Chapter 7 Aggregation CAR Configuration................................................................................ 7-1

7.1 Aggregation CAR Overview...............................................................................................7-1

7.2 Referencing Aggregation CAR in Traffic Behaviors..........................................................7-1

7.2.1 Configuration Prerequisites.....................................................................................7-1

7.2.2 Configuration Procedure.........................................................................................7-1

7.2.3 Configuration Examples..........................................................................................7-2

7.3 Displaying and Maintaining Aggregation CAR................................................................... 7-2

Chapter 8 VLAN Policy Configuration.........................................................................................8-1

8.1 VLAN Policy Overview....................................................................................................... 8-1

8.2 Configuring a VLAN Policy ................................................................................................8-2

8.2.1 Configuration Prerequisites.....................................................................................8-2

8.2.2 Configuration Procedure.........................................................................................8-2

8.3 Displaying and Maintaining VLAN Policies........................................................................8-2

8.4 VLAN Policy Configuration Examples................................................................................8-2

8.4.1 Network Requirements............................................................................................8-2

8.4.2 Configuration Procedure.........................................................................................8-3

Chapter 9 Traffic Mirroring Configuration ..................................................................................9-1

9.1 Traffic Mirroring Overview..................................................................................................9-1

9.2 Configuring Traffic Mirroring..............................................................................................9-1

Operation Manual – QoS

H3C S9500 Series Routing Switches Table of Contents

iii

9.2.1 Mirroring Traffic to a Port ........................................................................................9-1

9.2.2 Mirroring Traffic to the CPU ....................................................................................9-2

9.3 Displaying and Maintaining Traffic Mirroring .....................................................................9-3

9.4 Traffic Mirroring Configuration Examples..........................................................................9-3

Chapter 10 EACL Configuration ................................................................................................10-1

10.1 EACL Overview..............................................................................................................10-1

10.2 EACL Configuration Task List........................................................................................10-1

10.2.1 Configuring a Reflexive ACL Policy ....................................................................10-1

10.2.2 Configuring BT Traffic Limiting............................................................................10-3

10.2.3 Configuring a QoS Policy....................................................................................10-5

10.3 EACL Configuration Examples......................................................................................10-7

10.3.1 Reflexive ACL Configuration Examples.............................................................. 10-7

10.3.2 BT Traffic Limiting Configuration Examples........................................................10-8

10.4 Troubleshooting EACL.................................................................................................10-10

Chapter 11 Outbound Traffic Accounting Configuration........................................................11-1

11.1 Outbound Traffic Accounting Overview.........................................................................11-1

11.2 Configuring Outbound Traffic Accounting......................................................................11-1

11.3 Displaying and Maintaining Outbound Traffic Accounting.............................................11-2

Operation Manual – QoS

H3C S9500 Series Routing Switches Chapter 1 QoS Overview

1-1

Chapter 1 QoS Overview

When configuring QoS, go to these sections for information you are interested in:

z Introduction

z Traditional Packets Forwarding Application

z New Requirements Caused by New Applications

z Congestion: Causes, Impact, and Countermeasures

z Traffic Management Technologies

1.1 Introduction

Quality of Service (QoS) measures the service performance of service providers in

terms of client satisfaction. Instead of giving accurate marks, QoS emphasizes

analyzing what good or imperfect services are, and they come in what kind of

circumstances, so as to provide a cutting edge improvement.

In the Internet, QoS evaluates service performance for network packet forwarding. Due

to various services offered by the network, the evaluation for QoS will be based on

different aspects accordingly. Generally, QoS evaluates the service performance for

those network core requirements during packet forwarding process, such as delay, jitter

and packet loss ratio.

1.2 Traditional Packets Forwarding Application

On traditional IP networks, the devices treat all packets identically and handle them

with the first in, first out (FIFO) policy, assigning forwarding resources by arrival

sequence of packets. All the packets share the resources of the network devices. How

many resources the packets can obtain will completely depend on the time they arrive.

This service policy is called Best-effort, which delivers the packets to their destination

as it can, without any assurance and guarantee for delivery delay, jitter, packet loss

ratio, reliability and so on for packet forwarding.

The traditional Best-Effort service policy is only suitable for applications insensitive to

bandwidth and delay, such as WWW, file transfer and E-mail.

1.3 New Requirements Caused by New Applications

With the fast development of the network, more and more networks access the Internet.

The Internet has been expanded in terms of its scale, coverage and users quantities.

More and more users use Internet as their data transmission platform to implement

various applications.

Operation Manual – QoS

H3C S9500 Series Routing Switches Chapter 1 QoS Overview

1-2

Apart from traditional applications of WWW, E-mail and FTP, network users try to

expand some new applications, such as tele-education, telemedicine, video telephone,

videoconference and Video-on-Demand (VoD), on the Internet. And the enterprise

users expect to connect their regional branches together to develop some operational

applications through VPN technology, for instance, to access the database of the

company or monitor their remote equipment via Telnet.

Those new applications have one thing in common, i.e. high requirements for

bandwidth, delay, and jitter. For instance, videoconference and VOD need the

assurance of wide bandwidth, low delay and jitter. As for mission-critical applications,

such as transaction and Telnet, they may not require wide bandwidth but do require

lower delay and be handled by priority during congestion.

The new emerging applications demand higher service performance of IP network.

Better network services during packets forwarding are required other than simply

delivering the packets to their destination, such as providing user-specific bandwidth,

reducing packet loss ratio, avoiding congestion, regulating network traffic, setting

priority of the packets. To meet those requirements, the network should be provided

with better service capability.

1.4 Congestion: Causes, Impact, and Countermeasures

Network congestion occurs when inadequate resources are available for traffic. It can

degrade forwarding performance, introduce undesired delays, and hence degraded

service quality.

1.4.1 Causes

Congestion will easily occur in complex packet switching circumstances in the Internet,

with two cases illustrated in the following figure:

Figure 1-1 Traffic congestion causes

1) The packet streams enter a device from a high speed link and are forwarded via a

low speed link;

2) The packet streams enter a device from several interfaces with a same speed and

are forwarded through an interface with the same speed as well.

Operation Manual – QoS

H3C S9500 Series Routing Switches Chapter 1 QoS Overview

1-3

When traffic arrives at wire speed, congestion may occur for network resource

bottleneck.

Besides the bottleneck of link bandwidth, congestion will also be caused by resources

deficiency in normal packet forwarding, such as the deficiency of assignable processor

time, buffer and memory. In addition, congestion may occur if the arrival traffic is not

managed efficiently and the assignable network resources are inadequate.

1.4.2 Impact

Congestion may cause the following negative effects:

z Increase the delay and jitter of packet transmission

z Packet re-transmission caused by high delay

z Decrease the efficient throughput of network and lower the utilization of network

resources

z Intensified congestion can occupy too many network resources (especially in

memory), and the irrational assignment of resources even can lead to resource

block and breakdown for the system

It is obvious that congestion will make the traffics unable to obtain the resources in time

and degrade the service performance accordingly. No one wants congestion, but it

occurs frequently in complex environments where packet switching and multi-users

applications coexist. So it needs to be treated cautiously.

1.4.3 Countermeasure

A direct way to solve resources deficiency problem is to increase the bandwidth of

network; however, it cannot resolve all the problems caused by congestion.

A more effective method to solve the problem of QoS is to enhance the functions of

traffic control and resource allocation in the network, and to provide differentiated

services for applications with different service requirement in order to allocate and use

resources rightly. During the process of resources allocation and traffic control, the

direct or indirect factors that might cause network congestion should be controlled with

best effort to reduce the probability of congestion. As congestion occurs, resource

allocation should be balanced according to features and demands of applications, to

minimize the effects on QoS by congestion.

1.5 Traffic Management Technologies

Traffic classification, traffic policing, traffic shaping, congestion management, and

congestion avoidance are common traffic management techniques. They deliver the

following functions:

z Traffic classification: It is a prerequisite for differentiated service, to identify the

interested objects based on a certain matching rule.

Operation Manual – QoS

H3C S9500 Series Routing Switches Chapter 1 QoS Overview

1-4

z Traffic policing: polices the specification of particular traffics entering the switch.

When the traffics exceed the specification, then some restriction or punishment

measures can be taken to protect the commercial benefits of carriers and to

prevent network resources from being damaged.

z Traffic shaping: A traffic control measure of actively adjusting the output speed of

traffics, generally it can enable the traffic to adapt to the network resources

supplied by the downstream switch, to prevent the unwanted packet dropping and

congestion. Same as traffic policing, traffic shaping is implemented at the IP layer.

z Congestion management: handles resource competition during network

congestion. Generally, it stores the packets in the queue first, and then takes a

dispatching algorithm to assign the forwarding sequence of packets.

z Congestion avoidance: Exceeding congestion consumes network resources.

Congestion avoidance can monitor the usage status of network resources, and as

congestion becomes worse, actively take the policy of dropping packets through

adjusting traffic to resolve the overloading of the network.

Among those traffic management technologies, traffic classification is the basis. It is a

prerequisite for differentiated services, which identifies the interested packets with

certain matching rule. As for traffic policing, traffic shaping, congestion management

and congestion avoidance, they implement management to network traffic and

allocated resources from different aspects respectively to realize the differentiated

service.

Normally, QoS provides the following functions:

z Traffic classification

z Access control

z Traffic policing and shaping

z Congestion management

z Congestion avoidance

Operation Manual – QoS

H3C S9500 Series Routing Switches

Chapter 2 Traffic Classification and Traffic

Shaping Configuration

2-1

Chapter 2 Traffic Classification and Traffic

Shaping Configuration

When configuring traffic classification and traffic shaping, go to these sections for

information you are interested in:

z Traffic Classification Overview

z Traffic Shaping Overview

z Traffic Evaluation and Token Bucket

z Traffic Shaping Configuration

2.1 Traffic Classification Overview

2.1.1 Traffic classification

Traffic classification is the prerequisite and foundation for differentiated services, which

uses certain rules to identify the packets with certain features.

To discriminate flows, you can set traffic classification rules using the priority bits of ToS

(type of service) field in the IP packet header. Alternatively, the network administrator

may define a traffic classification policy, for instance, integrating information such as

source IP address, destination IP address, MAC address, IP protocol, or port number of

the applications to classify the traffic. In general, it can be a narrow range defined by a

quintuple (source IP address, source port number, destination IP address, destination

port number and the Transport Protocol), or can be all packets to a network segment.

In general, while packets being classified on the network border, the precedence bits in

the ToS byte of IP header are set so that IP precedence can be used as a direct packet

classification standard within the network. The queuing technologies can use IP

precedence to handle the packets. Downstream network can receive the packets

classification results from upstream network selectively, or re-classify the packets with

its own standard.

Traffic classification is used to provide differentiated service, so it must be associated

with certain kinds of traffic policing or resource-assignment mechanisms. To adopt what

kind of traffic policing action will depend on the current stage and load status of the

network. For example, to police the packets according to the committed rate when they

enter the network, to make traffic shaping before they flow out the nodes, to perform

queuing management in the event of congestion and to employ congestion avoidance

when congestion becomes worse.

Operation Manual – QoS

H3C S9500 Series Routing Switches

Chapter 2 Traffic Classification and Traffic

Shaping Configuration

2-2

2.1.2 Priority

Several priorities are described as follows:

Figure 2-1 DS field and ToS byte

As shown in

Figure 2-1, the ToS byte of IP header contains 8 bits: the first three bits (0

to 2) indicates IP precedence, valued in the range 0 to 7; the following 4 bits (3 to 6)

indicates ToS priority, valued in the range 0 to 15. In RFC2474, the ToS field of IP

packet header is redefined as DS field, where the DiffServ code point (DSCP) priority is

indicated by the first 6 bits (0 to 5), valued in the range 0 to 63. The remaining 2 bits (6

and 7) are reserved.

2.2 Traffic Shaping Overview

If no restrictions are imposed on the traffics from the users, bursting data sent by mass

users continuously will make the network become more congested. Thus for more

efficient network function and better network service for more users, the traffics from

the users must be restricted, for example, to restrict a traffic can only acquire the

specific assigned resources in certain time interval so as to prevent the network

congestion caused by excess burst.

Traffic shaping is a traffic monitoring policy to restrict the traffic and resources through

comparing with the traffic specification. To know whether the traffic exceeds the

specification or not is a prerequisite for traffic shaping. Then based upon the evaluation

result you can implement a regulation policy. Usually, Token Bucket is used to value the

traffic specification.

2.3 Traffic Evaluation and Token Bucket

I. Token bucket features

Token Bucket can be regarded as a container holding a number of tokens. The system

will put Tokens into the Bucket at a defined rate. In case the Bucket is full, the extra

Tokens will overflow and no more Tokens will be added.

Operation Manual – QoS

H3C S9500 Series Routing Switches

Chapter 2 Traffic Classification and Traffic

Shaping Configuration

2-3

Figure 2-2 Measuring the traffic with a token bucket

II. Measuring the traffic with Token Bucket

Whether or not the token quantity of the Token Bucket can satisfy the packets

forwarding is the basis for Token Bucket to measure the traffic specification. If enough

tokens are available for forwarding packets, traffic is regarded conforming the

specification (generally, one token is associated to the forwarding ability of one bit),

otherwise, non-conform or excess.

When measuring the traffic with Token Bucket, these parameters are included:

z Mean rate: The rate of putting Token into Bucket, i.e. average rate of the

permitting traffic. Generally set as CIR (Committed Information Rate).

z Burst size: Token Bucket’s capability, i.e. the maximum traffic size of every burst.

Generally, it is set as CBS (Committed Burst Size), and the bursting size must be

greater than the maximum packets size.

A new evaluation will be made when a new packet arrives. If there are enough tokens in

bucket for each evaluation, it shows that traffics are within the bound, and at this time

the amount of tokens appropriate for the packets forwarding rights, need to be taken

out. Otherwise, it shows that too many tokens have been used, and traffic

specifications are exceeded.

III. Complicated evaluation

Two Token Buckets can be configured to evaluate conditions that are more complex

and to implement more flexible regulation policy. For example, traffic policing has four

parameters, as follows:

z CIR (Committed information rate)

z CBS (Committed burst size)

Operation Manual – QoS

H3C S9500 Series Routing Switches

Chapter 2 Traffic Classification and Traffic

Shaping Configuration

2-4

z PIR (Peak information rate)

z EBS (Excess burst size)

It uses two token buckets, with the token-putting rate of every bucket set as CIR and

PIR and the capability of every bucket set as CBS and EBS (CBS < EBS, called C

bucket and E bucket), which represents different bursting class permitted. In each

evaluation, you may use different traffic control policies for different situations, such as

"C bucket has enough tokens”; "Tokens of C bucket are deficient, but those of E bucket

are enough”; "Tokens of C bucket and E bucket are all deficient”.

IV. Traffic policing

Typically, traffic policing is used to monitor the specification of certain traffic entering the

network and keep it within a reasonable bound, or it will make “penalty” on the

exceeding traffic so as to protect network resources and profits of carriers. For example,

it can restrict HTTP packets to occupy network bandwidth of no more than 50%. Once

finding the traffic of a connection exceeds, it may drop the packets or reset the

precedence of packets.

Traffic policing allows you to define match rules based on IP precedence or DiffServ

code point (DSCP). It is widely used by ISP to police the network traffic. Traffic policing

also includes the traffic classification service for the policed traffics, and depending

upon the different evaluation results, it will implement the pre-configured policing

actions, which are described as the following:

z Forward: For example, continue to forward the packets evaluated as “conform”.

z Drop: For example, dropping the packets evaluated as “not conform”.

V. Traffic shaping

Traffic shaping is an active way to adjust the traffic output rate.

The main difference between traffic shaping and traffic policing is: the packets to be

dropped in traffic policing will be stored during traffic shaping — generally they will be

put into buffer or queues, as shown in

Figure 2-3. Once there are enough tokens in

token bucket, those stored packets will be evenly sent. Another difference is that traffic

shaping may intensify delay, yet traffic policing seldom does so.

Operation Manual – QoS

H3C S9500 Series Routing Switches

Chapter 2 Traffic Classification and Traffic

Shaping Configuration

2-5

Figure 2-3 Traffic shaping diagram

For example, Switch A sends packets to Switch B. Switch B implements traffic policing

on those packets, and directly drops exceeding traffic.

To reduce unnecessary packet drop, GTS can be applied to the packets on the egress

interface of Switch A. The packets beyond the traffic specifications of GTS are stored in

Switch A. While sending the next set of packets, GTS takes out those packets from

buffer queues and sends them. Thus, all the packets sent to Switch B accord with the

traffic specification of Switch B.

 Note:

z Traffic shaping cannot be configured on ports with even port numbers on XP4CA

and XP4B boards, and traffic shaping configured on a port with an odd port number

takes effect on the incoming packets of both the port with the odd port number and

the port with the even port number (the odd port number plus one).

z Traffic shaping is not available to POS interfaces.

2.4 Traffic Shaping Configuration

Traffic shaping includes the following two types:

z Queue-based traffic shaping: set traffic shaping parameters for packets in a

queue.

z Traffic shaping applicable to all the traffic: set traffic shaping parameters for all the

traffic.

Operation Manual – QoS

H3C S9500 Series Routing Switches

Chapter 2 Traffic Classification and Traffic

Shaping Configuration

2-6

I. Configuring queue-based traffic shaping

Follow these steps to configure queue-based traffic shaping:

To do… Use the command… Remarks

Enter system view

system-view

—

Enter

Ethernet

interface

view

interface interface-type

interface-number

Enter

Ethernet

interface

view or

port

group

view

Enter

port

group

view

port-group { manual

port-group-name | aggregation

agg-id }

Use either the command

Configured in Ethernet

interface view, the

setting is effective on the

current interface only;

configured in port group

view, the setting is

effective on all the ports

in the port group.

Configure traffic

shaping on the

specific port or

ports in the specific

port group

qos gts queue queue-number cir

committed-information-rate [ cbs

committed-burst-size ]

Required

Display the traffic

shaping

configuration

information

display qos gts interface

[ interface-type interface-number ]

Optional

Available in any view

 Note:

z In traffic shaping configuration, the outgoing ports of XP4CA, XP4B, XP4DB,

GV48D, and GP48D boards support four queues, that is, the queue-number

argument is in the range of 0 to 3; this argument is in the range of 0 to 7 for the other

boards.

z For the description on the default value of CBS, refer to the related part in QoS

Commands.

Page is loading ...

H3C S9500 Series Operating instructions

H3C S9500 Series Operating instructions

H3C S9500 Series Operating instructions

Related papers

Other documents