Hi list, I have a problem using pjsip (pjproject-2.3 release) via the pjsua2 cpp api: Having implemented my own media port for transferring the data to and from one of our systems (spoken dialog system), it happens that the dialog management says to hang up a call. This of course happens in the media callbacks (since that's where the communication with the dialog system happens). Calling hangup() from this thread sometimes(!) leads to: pjsua_call.c !.Timed-out trying to acquire dialog mutex (possibly system has deadlocked) in pjsua_call_hangup(). Afterwards, the software crashes, so most likely something goes wrong with deletion of the call object. Is there any sort of locking I need to be doing in order to successfully hang up from a media callback? Do I need to defer the hangup to another thread altogether? I don't use any application mutexes, so according to https://trac.pjsip.org/repos/wiki/PJSUA_Locks I should not need to do anything there. Any hints? Regards, Thomas