Using NBAR to classify G.711 and G729 for QoS

Answered Question
May 5th, 2009

I'm working on a qos setup for a customer using a non cisco ip pbx, and I'm told it uses either g711 or g729 codecs depending on available licencies.

So I could get either a 64k or 8k call, which requires different qos policies.

Nbar seems to be the way to classify the traffic, based on RTP PT value, but G711 doesnt appear to have an assigned value.

Currently I'm thinking of configuring my classifier to match a PT value of 18 for G729, and assuming if its not G729 then it must be G711, but that seems a bit crude. Anyone any other ideas on how to do this?


I have this problem too.
0 votes
Correct Answer by Nicholas Matthews about 7 years 5 months ago

G.711 payload type should be 0 for G711ulaw and 8 for G.711alaw


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Overall Rating: 5 (1 ratings)
aacole Tue, 05/05/2009 - 12:24

Thanks for that, now I understand what PCMU and PCMA mean in the assignments list at


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