[Spce-user] rtpengine: does it ignore SRTP(SDES) with re-INVITEs?

[Anthony Alba]

I suspect the answer is yes; I just want to confirm that this is the
expected behaviour.

Scenario:

UAC: make SRTP call
sends INVITE:  rtpengine_manage() called in kamailio

UAC: call on hold
sends INVITE (a=sendonly) with new SDES (SRTP): rtpengine_manage()
called in kamailio

UAC: resumes call
sends INVITE with new SDES (SRTP): rtpengine_manage() called in kamailio

It seems that the first set of SDES are used throughout the call and
everything just works: the UACs are PJSIP (they don't seem to honor
the changing SDES), rtpengine also doesn't seemed to care about the
supposed "change" in SDES as stats gathering still works, and there
are no complaints that SRTCP failed to decrypt.

I.e., if UACs honored SDES change and rtpengine didn't, then I would
expect SRTCP to fail (for stats gathering). Conversely, if UACs
ignored new crypto and rtpengine didn't then SRTCP should also fail.

If seems that both PJSIP and rtpengine ignore mid-dialog SDES changes.
Can I confirm that it is the expected behaviour for rtpengine?


Thanks
AnthonyA