Dear all, When I make a call using my PRI line, all goes well, but suddently the call hangs up. I searched the asterisk logs, and I found that. Write to 55 failed: Unknown error 500 Short write: 0/15 (Unknown error 500) What does this mean? Why this occurs? How could I solve that? Someone could tell me if it was a primary error (the primary shows red alert in all its channels) or it could be a driver or config problem? Thanks in advance. VoipCrazy. Mar 27 14:28:00 DEBUG[20313] chan_zap.c: Got event Alarm(4) on channel 1 (index 0) Mar 27 14:28:00 VERBOSE[20313] logger.c: Write to 55 failed: Unknown error 500 Mar 27 14:28:00 VERBOSE[20313] logger.c: Short write: 0/15 (Unknown error 500) Mar 27 14:28:00 WARNING[20313] chan_zap.c: Detected alarm on channel 1: Red Alarm Mar 27 14:28:00 DEBUG[20313] chan_zap.c: disabled echo cancellation on channel 1 Mar 27 14:28:00 DEBUG[20313] channel.c: Didn't get a frame from channel: Zap/1-1 Mar 27 14:28:00 DEBUG[20313] channel.c: Bridge stops bridging channels SIP/7008-b6a158e0 and Zap/1-1 Mar 27 14:28:00 DEBUG[20313] chan_zap.c: Set option AUDIO MODE, value: ON(1) on Zap/1-1 Mar 27 14:28:00 DEBUG[20313] chan_zap.c: Hangup: channel: 1 index = 0, normal = 36, callwait = -1, thirdcall = -1 Mar 27 14:28:00 DEBUG[20313] chan_zap.c: disabled echo cancellation on channel 1 Mar 27 14:28:00 DEBUG[20313] chan_zap.c: Set option TDD MODE, value: OFF(0) on Zap/1-1 Mar 27 14:28:00 DEBUG[20313] chan_zap.c: Updated conferencing on 1, with 0 conference users Mar 27 14:28:00 DEBUG[20313] chan_zap.c: Set option AUDIO MODE, value: OFF(0) on Zap/1-1 Mar 27 14:28:00 DEBUG[20313] chan_zap.c: disabled echo cancellation on channel 1 Mar 27 14:28:00 VERBOSE[20313] logger.c: -- Hungup 'Zap/1-1' Mar 27 14:28:00 DEBUG[20313] app_dial.c: Exiting with DIALSTATUS=ANSWER. Mar 27 14:28:00 VERBOSE[20313] logger.c: == Spawn extension (macro-dialout-trunk, s, 20) exited non-zero on 'SIP/7008-b6a158e0' in macro 'dialout-trunk' Mar 27 14:28:00 VERBOSE[20313] logger.c: == Spawn extension (macro-dialout-trunk, s, 20) exited non-zero on 'SIP/7008-b6a158e0' Mar 27 14:28:00 VERBOSE[20313] logger.c: -- Executing Macro("SIP/7008-b6a158e0", "hangupcall") in new stack Mar 27 14:28:00 VERBOSE[20313] logger.c: -- Executing ResetCDR("SIP/7008-b6a158e0", "w") in new stack Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 2: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 2 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 3: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 3 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 4: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 4 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 5: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 5 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 6: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 6 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 7: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 7 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 8: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 8 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 9: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 9 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 10: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 10 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 11: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 11 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 12: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 12 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 13: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 13 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 14: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 14 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 15: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 15 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 17: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 17 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 18: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 18 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 19: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 19 Mar 27 14:28:00 WARNING[5155] chan_zap.c: Detected alarm on channel 20: Red Alarm Mar 27 14:28:00 WARNING[5155] chan_zap.c: Unable to disable echo cancellation on channel 20 Mar 27 14:28:00 NOTICE[5154] chan_zap.c: PRI got event: Alarm (4) on Primary D-channel of span 1 Mar 27 14:28:00 WARNING[5154] chan_zap.c: No D-channels available! Using Primary channel 16 as D-channel anyway!