QoS技术白皮书
杭州华三通信技术有限公司
www.h3c.com.cn
第3页, 共35页
目 录
1 概述 .......................................................................................................................................5
1.1 产生背景 ......................................................................................................................5
1.2 技术优点 ......................................................................................................................5
1.3 QoS服务模型简介........................................................................................................5
1.3.1 Best-Effort服务模型 ...........................................................................................6
1.3.2 IntServ服务模型.................................................................................................6
1.3.3 DiffServ服务模型 ...............................................................................................6
1.3.4 IntServ与DiffServ之间的互通.............................................................................7
2 IP QoS技
术实现.....................................................................................................................8
2.1 IP QoS功能总述...........................................................................................................8
2.1 流量分类和标记 ...........................................................................................................9
2.1.1 IP QoS业务分类...............................................................................................10
2.1.2 IPv6 QoS业务分类...........................................................................................11
2.1.3 以太网QoS业务分类 ........................................................................................11
2.2 拥塞管理 ....................................................................................................................14
2.2.1 先进先出队列（FIF
O）....................................................................................15
2.2.2 优先队列（PQ）..............................................................................................15
2.2.3 定制队列（CQ）..............................................................................................16
2.2.4 加权公平队列（WFQ） ...................................................................................18
2.2.5 基于类的加权公平队列（CBWFQ） ................................................................19
2.2.6 RTP优先队列...................................................................................................20
2.2.7 队列技术对比...................................................................................................21
2.3 拥塞避免 ....................................................................................................................22
2.3.1 传统的丢包策略 ...............................................................................................23
2.3.2 RED与WRED
..................................................................................................23
2.3.3 WRED和队列机制的关系.................................................................................24
2.4 流量监管与流量整形 ..................................................................................................24
2.4.1 约定访问速率（CAR） ....................................................................................25
2.4.2 通用流量整形（GTS） ....................................................................................26
2.4.3 物理接口总速率限制（LR） ............................................................................27
2.5 链路效率机制 .............................................................................................................28
2.5.1 链路分片与交叉（LFI） ...................................................................................28
