Apparently we've been having calls sporadically drop. We're using an IAX outbound trunk and SIP adapters on the inside. Below is a log excerpt detailing one of the calls which dropped, and it looks largely normal to me except for this: Jan 5 13:31:07 DEBUG[3776] channel.c: Didn't get a frame from channel: IAX2/teliax-2 Jan 5 13:31:07 DEBUG[3776] channel.c: Bridge stops bridging channels IAX2/teliax-2 and SIP/davidblanco-e02c Can missing one IAX frame result in a dropped call? Seems pretty fragile if that's the case. Would enabling the jitter buffer mitigate this? Any other suggestions? Jan 5 13:29:51 VERBOSE[29852] logger.c: -- Accepting UNAUTHENTICATED call from 208.139.204.245: > requested format = ulaw, > requested prefs = (g729|ulaw|g726|gsm), > actual format = gsm, > host prefs = (gsm|ulaw), > priority = mine Jan 5 13:29:51 VERBOSE[3776] logger.c: -- Executing Dial("IAX2/teliax-2", "SIP/davidblanco|30|tr") in new stack Jan 5 13:29:51 DEBUG[3776] chan_sip.c: Setting NAT on RTP to 524288 Jan 5 13:29:51 DEBUG[3776] chan_sip.c: Outgoing Call for davidblanco Jan 5 13:29:51 VERBOSE[3776] logger.c: -- Called davidblanco Jan 5 13:29:51 DEBUG[29854] chan_sip.c: (Provisional) Stopping retransmission (but retaining packet) on '58b5f3b5793b56376fc4a0bf180a8500@168.215.99.50' Request 102: Found Jan 5 13:29:51 DEBUG[29854] chan_sip.c: (Provisional) Stopping retransmission (but retaining packet) on '58b5f3b5793b56376fc4a0bf180a8500@168.215.99.50' Request 102: Found Jan 5 13:29:51 VERBOSE[3776] logger.c: -- SIP/davidblanco-e02c is ringing Jan 5 13:29:57 DEBUG[29854] chan_sip.c: Acked pending invite 102 Jan 5 13:29:57 DEBUG[29854] chan_sip.c: build_route: Contact hop: <sip:davidblanco@192.168.1.50:5060> Jan 5 13:29:57 VERBOSE[3776] logger.c: -- SIP/davidblanco-e02c answered IAX2/teliax-2 Jan 5 13:29:57 DEBUG[29852] chan_iax2.c: Ooh, voice format changed to 2 Jan 5 13:29:59 DEBUG[29852] chan_iax2.c: Peer lastms 70, historicms 70, maxms 2000 Jan 5 13:30:15 DEBUG[29852] chan_iax2.c: Peer lastms 28, historicms 28, maxms 2000 Jan 5 13:30:59 DEBUG[29852] chan_iax2.c: Peer lastms 71, historicms 71, maxms 2000 Jan 5 13:31:07 DEBUG[29852] chan_iax2.c: Immediately destroying 2, having received hangup Jan 5 13:31:07 DEBUG[3776] channel.c: Didn't get a frame from channel: IAX2/teliax-2 Jan 5 13:31:07 DEBUG[3776] channel.c: Bridge stops bridging channels IAX2/teliax-2 and SIP/davidblanco-e02c Jan 5 13:31:07 DEBUG[3776] chan_sip.c: update_call_counter(davidblanco) - decrement call limit counter Jan 5 13:31:07 DEBUG[3776] app_dial.c: Exiting with DIALSTATUS=ANSWER. Jan 5 13:31:07 VERBOSE[3776] logger.c: == Spawn extension (default, 6078210976, 1) exited non-zero on 'IAX2/teliax-2' Jan 5 13:31:07 DEBUG[3776] cdr_addon_mysql.c: cdr_mysql: inserting a CDR record. ***CDR STUFF OMITTED*** Jan 5 13:31:07 DEBUG[3776] chan_iax2.c: We're hanging up IAX2/teliax-2 now... Jan 5 13:31:07 DEBUG[3776] chan_iax2.c: Really destroying IAX2/teliax-2 now... Jan 5 13:31:07 VERBOSE[3776] logger.c: -- Hungup 'IAX2/teliax-2'