Cisco Video Over IP QoS 配置　

　　在做 Video over IP 时候一定要确保双方的 viewstation 以太网口带宽和双工都是一致的，否者会出现有一个方向的视频质量特别差的问题。

　　这里有个很好的 Video QoS 例子，用的是 2M 的专线，需要在 viewstation 上作优先级设置的，不然 QoS 策略无法被激活的！关于 polycom viewstation 的 QoS precedence 设置请您参考 Polycom Viewstation 的设置。

　　This is one I did a couple of weeks ago (below)- only acl 100 was getting hit. It did do the trick and the picture was clear. the priority value is actually the bandwidth in Kilobits. You will need to be able to set the precedence on the video traffic to critical - this was done on the viewstations that were sending out the video packets in this case..

　　class-map match-all video-control

　　match access-group 101

　　class-map match-all video

　　match access-group 100

　　!

　　!

　　policy-map QoS-Policy

　　class video

　　priority 800 553058304

　　class video-control

　　bandwidth 8

　　class class-default

　　fair-queue

　　!

　　!

　　!

　　!

　　!

　　interface Multilink1

　　ip address 172.22.254.2 255.255.255.0

　　ip tcp header-compression iphc-format

　　no ip mroute-cache

　　load-interval 30

　　service-policy output QoS-Policy

　　ppp multilink

　　ppp multilink fragment-delay 10

　　ppp multilink interleave

　　multilink-group 1

　　ip rtp header-compression iphc-format

　　!

　　interface Serial0/0

　　bandwidth 2048

　　no ip address

　　encapsulation ppp

　　no ip mroute-cache

　　load-interval 30

　　no fair-queue

　　serial restart_delay 0

　　ppp multilink

　　multilink-group 1

　　!

　　access-list 100 permit ip any any precedence critical

　　access-list 101 permit ip any any precedence flash

　　access-list 101 permit ip any any dscp af31