I’m running 18.104.22.168 (compiled from source) and I’m haunted by a very annoying problem.
On ChanSpy and MixMonitor recordings, on some of the destinations that we’re dialing out, the party we’re calling sounds very distorted.
The local phone is connected to asterisk via SIP (and using alaw), the outgoing trunk is also SIP (using g729).
I must also mention that on Yealink phones we’re using, everything is crystal clear
Tried the following:
-Change the format in which the recordings are made (from Wav to Ogg)
-Changed the recording destination to a tmpfs directory
-Force a jitter buffer
-Tried various timing modules (dahdi - there is a PRI, timerfd and pthread)
-Changed our SIP clients (the Yealink phones) to g729
As a last resort, moved the g729 transcoding to another 22.214.171.124 machine with two trunks only:
SIP to the VoIP provider and IAX to the previous machine (which is now only handling alaw). Still no improvement.
Must mention that the CPU load is insignificant in both scenarios.
Again, only certain destinations (local landlines) are affected by this problem.
The VoIP provider insists on the fact that they are only using g729.a (so in theory not a VAD problem).
I can provide audio samples for anyone interested.
Thank you for your time.