Symptom

ASR 1001 running IOS XE 16.6.2 may crash when the system handles numerous number of RTP media connection loops. This issue was observed when the incoming SIP call from service provider was answered by a TCL script in CUBE. The TCL script was configured to play a prompt to incoming callers. Decode of the core dump file will show a backtrace at "rbuf_ooh_handler" and "inject_packet_handler_no_attn_sync" functions. The command output "show voip rtp connections" can be used to identify the media loop. Router#sh voip rtp connections VoIP RTP Port Usage Information: Max Ports Available: 19999, Ports Reserved: 101, Ports in Use: 496 Port range not configured Min Max Ports Ports Ports Media-Address Range Port Port Available Reserved In-use ------------------------------------------------------------------------------ Global Media Pool 8000 48198 19999 101 496 ------------------------------------------------------------------------------ VoIP RTP active connections : 492 1216443 1216435 38706 35484 192.168.1.10 192.168.1.0 NO NA 493 1216446 -1 42240 0 192.168.1.10 0.0.0.0 NO NA 494 1216456 1216457 35484 38706 192.168.1.10 192.168.1.10 NO NA 495 1216457 1216456 15850 13182 172.16.1.10 172.16.2.10 NO NA 496 1216458 1216459 13182 15850 172.16.2.10 172.16.1.10 NO NA Found 496 active RTP connections Router#

Conditions

Several RTP Media connections loops must be associated with a single call in order for this crash to occur.

Workaround

Review and update the call routing configuration in CUBE and CUCM (example: call forwarding loops) to eliminate the possibility of having numerous RTP media connection loop for a single call.

Further Problem Description