I am trying to track down an issue where FreeTDM seems to get confused about the state of channels on my PRI. The state seems to occur on origination; FreeTDM opens a channel, and immediately closes it, logging REQUESTED_CHAN_UNAVAIL. The channel then sits in the HANGUP state, preventing inbound calls and logging the following error. 2015-02-03 08:25:04.774438 [ERR] ftmod_libpri.c:1883 [s1c1][1:1] -- Selected channel is already in use I can resolve this by restarting Freeswitch, but it is obviously less-than-ideal. A bit of relevant logging is at the end of this message. It seems to occur immediately after a hangup on the same channel; could I be triggering a race condition? https://freeswitch.org/jira/browse/OPENZAP-220 seems to have similar symptoms, but manifests as a different error number. I upgraded Freeswitch last week (1.5.15b git 608d3e2 2015-01-22 09:09:59Z 64bit) to ensure that I had the patch referenced by the ticket. Is it possible that this could be a cabling issue? We're running Freeswitch on FreeBSD 10.0 amd64. I'm happy to provide any other information that would be useful. I'm [relatively] new to Freeswitch, so please be gentle ;-). Thank you, Tom 2015-02-03 14:34:23.437947 [DEBUG] ftmod_libpri.c:1451 -- Hangup ACK on channel 1:1 2015-02-03 14:34:23.437947 [DEBUG] ftmod_libpri.c:1460 [s1c1][1:1] Changed state from HANGUP to HANGUP_COMPLETE 2015-02-03 14:34:23.437947 [DEBUG] ftdm_state.c:541 [s1c1][1:1] Executing state processor for HANGUP_COMPLETE 2015-02-03 14:34:23.437947 [DEBUG] ftmod_libpri.c:942 -- 1:1 STATE [HANGUP_COMPLETE] 2015-02-03 14:34:23.437947 [DEBUG] ftmod_libpri.c:950 [s1c1][1:1] Completed state change from HANGUP to HANGUP_COMPLETE in 0 ms 2015-02-03 14:34:23.437947 [DEBUG] ftmod_libpri.c:1268 [s1c1][1:1] Changed state from HANGUP_COMPLETE to DOWN 2015-02-03 14:34:23.437947 [DEBUG] ftdm_state.c:541 [s1c1][1:1] Executing state processor for DOWN 2015-02-03 14:34:23.437947 [DEBUG] ftmod_libpri.c:942 -- 1:1 STATE [DOWN] 2015-02-03 14:34:23.437947 [DEBUG] ftmod_libpri.c:950 [s1c1][1:1] Completed state change from HANGUP_COMPLETE to DOWN in 0 ms 2015-02-03 14:34:23.437947 [DEBUG] ftdm_io.c:3194 [s1c1][1:1] DTMF debug is already disabled 2015-02-03 14:34:23.437947 [DEBUG] ftdm_io.c:3226 [s1c1][1:1] No need to disable input dump 2015-02-03 14:34:23.437947 [DEBUG] ftdm_io.c:3257 [s1c1][1:1] No need to disable output dump 2015-02-03 14:34:23.437947 [DEBUG] mod_freetdm.c:2707 got clear channel sig [RELEASED] 2015-02-03 14:34:23.437947 [DEBUG] ftdm_io.c:6873 Cleared call with id 37 2015-02-03 14:34:23.437947 [DEBUG] ftdm_io.c:2999 [s1c1][1:1] channel done 2015-02-03 14:34:23.437947 [DEBUG] ftmod_libpri.c:978 -- Closed channel 1:1 2015-02-03 14:34:23.679236 [DEBUG] switch_ivr_originate.c:2099 Parsing global variables 2015-02-03 14:34:23.679236 [DEBUG] switch_event.c:1688 Parsing variable [ignore_early_media]=[true] 2015-02-03 14:34:23.679236 [DEBUG] switch_event.c:1688 Parsing variable [file]=[46475.tif] 2015-02-03 14:34:23.679236 [DEBUG] switch_event.c:1688 Parsing variable [jobid]=[293102] 2015-02-03 14:34:23.679236 [INFO] ftmod_zt.c:671 Setting echo cancel to 64 taps for 1:1 2015-02-03 14:34:23.679236 [DEBUG] mod_freetdm.c:403 Set codec PCMU 20ms 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.679236 [DEBUG] mod_freetdm.c:1251 Connect outbound channel FreeTDM/1:1/18019941076 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.679236 [NOTICE] switch_channel.c:1055 New Channel FreeTDM/1:1/18019941076 [8d09030a-e4ab-e411-905b-0026b95c8602] 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.679236 [DEBUG] mod_freetdm.c:1260 (FreeTDM/1:1/18019941076) State Change CS_NEW -> CS_INIT 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.679236 [DEBUG] switch_core_session.c:1388 Send signal FreeTDM/1:1/18019941076 [BREAK] 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.679236 [DEBUG] mod_freetdm.c:1279 Attached session 8d09030a-e4ab-e411-905b-0026b95c8602 to channel 1:1 2015-02-03 14:34:23.679236 [DEBUG] mod_freetdm.c:1767 [s1c1][1:1] Changed state from DOWN to DIALING 2015-02-03 14:34:23.778359 [DEBUG] ftdm_state.c:541 [s1c1][1:1] Executing state processor for DIALING 2015-02-03 14:34:23.778359 [DEBUG] ftmod_libpri.c:942 -- 1:1 STATE [DIALING] 2015-02-03 14:34:23.778359 [DEBUG] mod_freetdm.c:2707 got clear channel sig [DIALING] 2015-02-03 14:34:23.778359 [DEBUG] ftmod_libpri.c:950 [s1c1][1:1] Completed state change from DOWN to DIALING in 95 ms 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:472 (FreeTDM/1:1/18019941076) Running State Change CS_INIT 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:512 (FreeTDM/1:1/18019941076) State INIT 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] mod_freetdm.c:430 (FreeTDM/1:1/18019941076) State Change CS_INIT -> CS_ROUTING 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_session.c:1388 Send signal FreeTDM/1:1/18019941076 [BREAK] 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:512 (FreeTDM/1:1/18019941076) State INIT going to sleep 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:472 (FreeTDM/1:1/18019941076) Running State Change CS_ROUTING 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:528 (FreeTDM/1:1/18019941076) State ROUTING 2015-02-03 14:34:23.778359 [DEBUG] mod_freetdm.c:453 FreeTDM/1:1/18019941076 CHANNEL ROUTING 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_ivr_originate.c:67 (FreeTDM/1:1/18019941076) State Change CS_ROUTING -> CS_CONSUME_MEDIA 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_session.c:1388 Send signal FreeTDM/1:1/18019941076 [BREAK] 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:528 (FreeTDM/1:1/18019941076) State ROUTING going to sleep 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:472 (FreeTDM/1:1/18019941076) Running State Change CS_CONSUME_MEDIA 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:547 (FreeTDM/1:1/18019941076) State CONSUME_MEDIA 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.778359 [DEBUG] switch_core_state_machine.c:547 (FreeTDM/1:1/18019941076) State CONSUME_MEDIA going to sleep 2015-02-03 14:34:23.799281 [DEBUG] ftmod_libpri.c:1466 -- Hangup on channel 1:1 2015-02-03 14:34:23.799281 [DEBUG] ftmod_libpri.c:1479 [s1c1][1:1] Changed state from DIALING to TERMINATING 2015-02-03 14:34:23.799281 [DEBUG] ftdm_state.c:541 [s1c1][1:1] Executing state processor for TERMINATING 2015-02-03 14:34:23.799281 [DEBUG] ftmod_libpri.c:942 -- 1:1 STATE [TERMINATING] 2015-02-03 14:34:23.799281 [DEBUG] ftmod_libpri.c:950 [s1c1][1:1] Completed state change from DIALING to TERMINATING in 0 ms 2015-02-03 14:34:23.799281 [DEBUG] ftdm_io.c:6216 [s1c1][1:1] Scheduling safety hangup timer 2015-02-03 14:34:23.799281 [DEBUG] mod_freetdm.c:2707 got clear channel sig [STOP] 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.799281 [NOTICE] mod_freetdm.c:2731 Hangup FreeTDM/1:1/18019941076 [CS_CONSUME_MEDIA] [REQUESTED_CHAN_UNAVAIL] 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.799281 [DEBUG] switch_channel.c:3222 Send signal FreeTDM/1:1/18019941076 [KILL] 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.799281 [DEBUG] switch_core_session.c:1388 Send signal FreeTDM/1:1/18019941076 [BREAK] 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.799281 [DEBUG] switch_core_state_machine.c:472 (FreeTDM/1:1/18019941076) Running State Change CS_HANGUP 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.799281 [DEBUG] switch_core_state_machine.c:735 (FreeTDM/1:1/18019941076) Callstate Change DOWN -> HANGUP 8d09030a-e4ab-e411-905b-0026b95c8602 2015-02-03 14:34:23.799281 [DEBUG] switch_core_state_machine.c:737 (FreeTDM/1:1/18019941076) State HANGUP 2015-02-03 14:34:23.799281 [DEBUG] mod_freetdm.c:544 [1:1] FreeTDM/1:1/18019941076 CHANNEL HANGUP ENTER 2015-02-03 14:34:23.799281 [DEBUG] mod_freetdm.c:623 [s1c1][1:1] Changed state from TERMINATING to HANGUP 2015-02-03 14:34:23.819045 [DEBUG] switch_ivr_originate.c:3719 Originate Resulted in Error Cause: 44 [REQUESTED_CHAN_UNAVAIL] 2015-02-03 14:34:23.918415 [DEBUG] ftdm_state.c:541 [s1c1][1:1] Executing state processor for HANGUP 2015-02-03 14:34:23.918415 [DEBUG] ftmod_libpri.c:942 -- 1:1 STATE [HANGUP] 2015-02-03 14:34:23.918415 [DEBUG] ftmod_libpri.c:950 [s1c1][1:1] Completed state change from TERMINATING to HANGUP in 109 ms 2015-02-03 14:34:23.918415 [DEBUG] mod_freetdm.c:643 [1:1] FreeTDM/1:1/18019941076 CHANNEL HANGUP EXIT