Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

VoIP UDP codec decoding

Is there a way to verify the codec that's encapsulated in a udp packet if you are performing a capture on the ingress of a router or switch port?

Thanks,

Brandon

5 REPLIES
New Member

Re: VoIP UDP codec decoding

You can use the Ethereal or Wireshark applications for decode the RTP packets and see the codec.

Re: VoIP UDP codec decoding

Wireshark is really nice


Make sure to uncheck the boxes for Enable MAC name resolution and Enable transport name resolution

Super Bronze

Re: VoIP UDP codec decoding

Hi

Well - as suggested the Wireshark community is probably a better place to start...

That said... try:

1) Make sure that you have identified the two streams as RTP. Wireshark doesn't see stuff as RTP initially, so you have to click a packet from each stream direction and set 'Decode As... ' to RTP.

2) When you do Telephone/RTP/Show All Streams you should see a stream for each direction, then click on one and hit analyse...

3) If it won't export 'both' directions, try one direction.. if that works then you haven't marked both streams as RTP, or there's another problem.

Would suggest posting your capture here or at wireshark in that case.

Regards

Aaron

Please rate helpful posts..

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

Re: VoIP UDP codec decoding

to fix my problem,

i had to Make sure to uncheck the boxes for Enable MAC name resolution and Enable transport name resolution.

without that I was not able to save the payload to an audio file

thanks

Hall of Fame Super Gold

Re: VoIP UDP codec decoding

Wireshark questions should go to Wireshark community.

704
Views
0
Helpful
5
Replies