I may be doing something really stupid but I could not figure out what. I am testing call recording using both MR and SSC on remote labs. To test my application, I dial from one extension to another and record the call. I am unable to send audio on the VPN, and therefore I expect silence audio media to be streamed.

For both MR and SSC, I get the media, however the payloads are vastly different (caputred on wireshark) -

For MR, the payload data is the following -

80007136a73e027c43b47936fe7e7e7ffffefe7efe7fff7e7ffffeff7fff7ffe7efefefe7ffefe7e7e7f7efffeff7e7efefefefe7e7e7efffe7efefefffffeff7eff7ffffffffe7ffefe7eff7f7f7f7efe7efe7efffefeff7ffeff7fff7f7e7ffe7f7f7efefefefffe7eff7e7ffffefe7f7f7efe7ffe7f7f7f7ffffeff7e7efe7efeffff7efe7f7e7eff7efe7efffe7efffffeff7e7f7efffffe7f7ffe7eff7f7efe7ffffefffeff7efeff7f

For SSC, the payload data is -

8000460c0e07801856bd3b6effffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff

The size of the payload for both is the same.

For MR, I have 5 extensions configured 40016, 40017..till 40020.

For SSC, I configure 40016, 40017 and 40018 as my calling extensions. I have used 40019 and 40020 as my recording device extensions.

The media parameters are the same for both.

Any hint on how to debug the issue ?

Thanks

For MR, since you are getting the audio that the main device is getting verbatim, I think the reason you see 7e, fe and ff bytes (I am assuming that is PCM audio), is due to the side tone ( a little bit of the speaker's audio is fed back to the speaker so they hear themselves speak). In the SSC case this is done as well, but since you have a slightly different audio circuit in the SSC case as compared to the MR case, I am guessing that causes the difference you see. Till you have audio flowing in your test environment I would ignore this difference.