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Community Member

QOS using video over IP

We are using Polycom video systems on our company and

I was assign to do it over the private IP backbone which consist of fractional T's to Europe. The first router hop bw is 1024 M and the second one is 1920K.

I am presently using Low latency queueing which prioritized 768K of traffic over the serial connections. No other special configuration in configured on the routers except this Class Based WFQ

with priority :

sh policy

Policy Map wan

Class video

Weighted Fair Queueing

Strict Priority

Bandwidth 768 (kbps) Burst 19200 (Bytes)

Anybody out there who can help me with the configuration because even when the network is not congested, there are some glitches on the video and sometimes frozen. appreciate any help extended to me on this.Here is my config on each the 3 router:

class-map video

match access-group 101



policy-map wan

class video

priority 768

access-list 101 permit ip any any precedence critical

int ser 1/0/X



service-policy output wan




Cisco Employee

Re: QOS using video over IP

It may be that you don't want to allow anything with precedence critical. Unless you have a policy implemented somewhere which sets everything but video to something other than IP precedence 5 then you could be giving a strict priority to non-video packets.

It may be a good idea to make the access-list somehow more selective, for instance adding IP address ranges, protocols (UDP), and/or port numbers for the video traffic.

Also, do you have kind of admission control mechanism in place to make sure that the total traffic used for videoconferencing does not exceed the 768k size?

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