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how to identify netmeeting traffic for voip


can anyone tell me how can i identify voip traffic on a network using 3640 router as im using netmeeting & no voice modules as such.Since im working on CBWFQ/LLQ, thats why without knowing the UDP/RTP port number for netmeeting,how can i identify it & later on assign priority to it.

secondly im using VLC player for video streaming ,where it says in the network settings it using UDP/RTP port 1234.

pls guide.



Re: how to identify netmeeting traffic for voip

NBAR, network based application recognition, will identify RTP traffic.

The RTP payload type is the data transported by RTP in a packet, for example audio samples or compressed video data.

NBAR RTP Payload Type Classification not only allows one to statefully identify real-time audio and video traffic, but it also can differentiate on the basis of audio and video CODECs to provide more granular Quality of Service. The RTP Payload Type Classification feature, therefore, looks deep into the RTP header to classify RTP packets.

NBAR RTP Payload Type Classification was first introduced in Cisco IOS Release 12.2(8)T and is also available in Cisco IOS Release 12.1(11b)E.

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Re: how to identify netmeeting traffic for voip

Hi ,

I think NBAR would help you to classify rtp traffic based on their port values or entire RTP traffic , but not sure whether it would help you to identify the rtp ports used by your application.

If your applications are voice based and uses rtp , then go for a " match protocol rtp " and classify the traffic , or if your network is small , then match based on the ip which uses the netmeeting and other applications and send it via the decided queue

Hope this helps


vanesh k

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