Today I face out a very strange problem with a Vodia PBX (5.4.1 (Vodia mini PBX (Debian))) and a Snom M300/M65 set. If I enable TLS on the phone I had a very loud background noise before and during the call. All disappear if I use UDP as protocol on the phone instead of the UDP. How that is possible? I attached the audio file I recorded
In fact I disabled the TLS on the phone and SRTP, the problem is that I still have 20 snom phones at this customer that now they are working with TLS, but I don't know for how long more it will be ok. How I can check the reason of the SRTP key negotation fails? If the solution is upgrading to a recent version of PBX, is the problem related to some Certificate expiration? If yes, how check when is the expiration? Just to be sure that nothing will happen until that date, thanks.