Wireshark call recording via SBC

[Goran Cvijanovic]

Hello,

I made a capture file from my phone connected to the PBX via SBC to the remote phone connected as a STUN phone and while I can see 2 call legs, one from phone to sbc and another vice versa, I'm not able to play the audio of that call within my wireshark.

Out call is using Opus codec, and SBC is using encryption.

Anyone able to tell me what's the problem and what to do in order to get sound recorded?
Thanks!

 

[cobaltit]

I think this might have something to do with it:

RTP stream is empty or codec is unsupported

 

[leejor]

At what point in the network are you doing the capture?
Between the phone and SBC...between SBC and 3CX...between 3CX and Stun set?

 

[cobaltit]

At what point in the network are you doing the capture?
Between the phone and SBC...between SBC and 3CX...between 3CX and Stun set?

I assumed on the phone itself based off the first sentence but that is a good point to clarify.

 

[Goran Cvijanovic]

PhoneA---SBC------3CX AWS-------STUN PhoneB
I captured traffic from the Phone's A web interface.
Is it a problem in Opus codec not supported by the Wireshark, or traffic is encrypted between Phone A and SBC, or even something else?

 

[leejor]

Did you see...

https://osqa-ask.wireshark.org/ques...e-in-context-of-opus-codec-cannot-decode-opus

and...

https://stackoverflow.com/questions/23683317/decode-opus-48-using-wireshark

 

[cobaltit]

The phones have no way to decrypt what 3CX is doing. The SBC only encrypts the tunnel between the SBC and 3CX.

 

[cobaltit]

Well, let me clarify that. By default, 3CX merely obfuscates the data in the tunnel. If you enable encryption, then it also encrypts. But either way that's only the traffic passing through the tunnel.