We are experiencing an odd issue. We have many calls that don't drop, but some do after being up a minute or two. The reason code is NORMAL_TEMPORARY_FAILURE and the sip status that is triggering that is 503 (Service Unavailable). With only one or two calls up at a time, I don't think it's a session limit issue (set to 1000). Here is the console log from just before the 503 status - any help is greatly appreciated! 2010-01-27 12:49:11.879251 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [calling][0] 2010-01-27 12:49:11.899334 [INFO] sofia.c:597 Update Callee ID to "400" <400> 2010-01-27 12:49:11.919018 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [ready][200] 2010-01-27 12:49:11.919018 [DEBUG] sofia.c:4011 Duplicate SDP v=0 o=- 1264621687 1264621687 IN IP4 192.168.0.46 s=Polycom IP Phone c=IN IP4 192.168.0.46 t=0 0 a=sendrecv m=audio 2222 RTP/AVP 0 8 18 127 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=rtpmap:127 telephone-event/8000 2010-01-27 12:50:06.068999 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [calling][0] 2010-01-27 12:50:06.108877 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [ready][200] 2010-01-27 12:50:06.108877 [DEBUG] sofia.c:4011 Duplicate SDP v=0 o=- 1264621687 1264621687 IN IP4 192.168.0.46 s=Polycom IP Phone c=IN IP4 192.168.0.46 t=0 0 a=sendrecv m=audio 2222 RTP/AVP 0 8 18 127 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=rtpmap:127 telephone-event/8000 2010-01-27 12:51:05.259614 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [calling][0] 2010-01-27 12:51:05.298972 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [ready][200] 2010-01-27 12:51:05.298972 [DEBUG] sofia.c:4011 Duplicate SDP v=0 o=- 1264621687 1264621687 IN IP4 192.168.0.46 s=Polycom IP Phone c=IN IP4 192.168.0.46 t=0 0 a=sendrecv m=audio 2222 RTP/AVP 0 8 18 127 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=rtpmap:127 telephone-event/8000 2010-01-27 12:52:05.369138 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [calling][0] 2010-01-27 12:52:05.399251 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [ready][200] 2010-01-27 12:52:05.399251 [DEBUG] sofia.c:4011 Duplicate SDP v=0 o=- 1264621687 1264621687 IN IP4 192.168.0.46 s=Polycom IP Phone c=IN IP4 192.168.0.46 t=0 0 a=sendrecv m=audio 2222 RTP/AVP 0 8 18 127 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=rtpmap:127 telephone-event/8000 2010-01-27 12:53:09.599069 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [calling][0] 2010-01-27 12:53:09.599069 [DEBUG] sofia.c:4003 Channel sofia/internal/400@192.168.0.31 entering state [terminating][503] 2010-01-27 12:53:09.599069 [NOTICE] sofia.c:4647 Hangup sofia/internal/400@192.168.0.31 [CS_EXECUTE] [NORMAL_TEMPORARY_FAILURE] 2010-01-27 12:53:09.599069 [DEBUG] switch_ivr_bridge.c:466 sofia/internal/400@192.168.0.31 ending bridge by request from write function