I can't get Wireshark v2.4.3 to playback G7221 RTP.

asked 2017-12-14 10:36:20 +0000

Ben gravatar image

updated 2017-12-14 13:15:16 +0000

When trying to playback from RTP analysis it states the codec is not supported. The release notes for v2.4 however states it supports G722 using spanDSP library. Any ideas how I can get playback to work for G722?

I have also tried to save the RTP stream as a RAW and import it into Audacity but I cannot find any import encoding or "endian" info for G722 so all I get is static.

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Your Question title says G7221 but in the text you talk about G722. The two are different codecs with different legal status - G.722 patents have expired so it is license-free now while G.722.1 is royalty-free but still licensed so you have to sign a contract with Polycom to get the right to distribute it.

sindy gravatar imagesindy ( 2017-12-14 11:57:33 +0000 )edit

Which OS are you running on?

grahamb gravatar imagegrahamb ( 2017-12-14 11:58:00 +0000 )edit

Thank you for your replies.

I am running Windows 10 with Wireshark 2.4.3

The wireshark trace is from a Cisco Jabber to Jabber test conversation. The RTP analysis states the payload is G7221. I was not aware of the differing legal status for G.722 and G.722.1. How would I then be able to legally playback the G.722.1 RTP stream? Any suggestions would be greatly appreciated.

Ben gravatar imageBen ( 2017-12-14 13:08:17 +0000 )edit

This path takes us away from Wireshark, but is still covered by the "protocols" clause of the mission of this site I guess :-)

Back in times when G.729's patents were still valid, I was using SIPp's play_pcap_audio feature to replay audio streams which had to be reconstructed into sound to a SIP terminal supporting the codec in question.

sindy gravatar imagesindy ( 2017-12-14 14:05:47 +0000 )edit