AFAIR Wireshark cannot play our RTP streams because it has a very limited set of codecs, mostly focusing on regular VoIP audio.

Cheers, Domi

24.02.2023 dátummal, 1:29 időpontban Neels Hofmeyr nhofmeyr@sysmocom.de írta:

On Wed, Feb 22, 2023 at 11:58:24PM +0330, morteza ali Ahmadi wrote:

...

I have aggregated all RTP packets payload. How can I convert the aggregated bytes to a hearable audio?

Firstly you need to be aware that 3G audio uses IuUP -- the RTP payload includes an IuUP header followed by the AMR audio data. To see this in wireshark, you need to go to Preferences / Protocols / IuUP and mark [x] Dissect IuUP Payload bits.

osmo-mgw has implemented the IuUP to AMR conversion: if one side of an MGCP endpoint has VND.3GPP.IUFP and the other has AMR, osmo-mgw will decapsulate the AMR from the IuUP, i.e. forward plain AMR.

Next I guess you will convert the AMR to something you can play back, AFAIK https://gitea.osmocom.org/osmocom/gapk is capable of that?

Also wireshark is supposed to be able to play back an RTP stream. See the menu item Telephony / RTP. It hasn't worked for me yet, not sure what I'm doing wrong, but I also never tried for more than two minutes.

This is a rough outline, you'll have to figure out all the details...

~N