[Users] looping problem

I have experienced a problem (looping problem?) in the system. From the log (ngrep) below, the cancel message issues a loop and it will affect the performance of the system. User can't dial/receive call after the loop happened. How and why this loop will created? Does it related to the rtpproxy that I am using in the system? Any one can give me some hints? Thanks, unplug Note: 10.200.0.228 is an openser server. filter: (ip) and ( port 5060 ) U 10.200.0.228:5060 -> 10.200.0.228:5060 CANCEL sip:85234163634@10.200.0.228 SIP/2.0. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.3ffb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.2ffb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.1ffb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.0ffb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.fefb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.eefb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.defb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.cefb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.befb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.aefb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.9efb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.8efb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.7efb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.6efb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.4efb2934.0. Via: SIP/2.0/UDP 10.0.0.92:5060;branch=z9hG4bKrmPCJR8Xm6JKY4o8. Max-Forwards: 55. User-Agent: Koncept KE10XX v4.32.14 00-09-45-0a-fc-29. From: "871966760539" <sip:871966760539@10.200.0.228>;tag=ckRP8FNJugUqMOjy. To: "85234163634" <sip:85234163634@10.200.0.228>. Call-ID: WfigvZ4YJatMKamV(a)10.0.0.92. Contact: <sip:871966760539@10.0.0.92:5060>. CSeq: 1 CANCEL. Content-Length: 0. . # U 10.200.0.228:5060 -> 10.200.0.228:5060 SIP/2.0 408 Request Timeout. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.201bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.101bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.001bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.ff0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.ef0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.df0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.cf0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.bf0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.af0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.9f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.8f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.7f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.6f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.5f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.4f0bae66.0. Via: SIP/2.0/UDP 10.0.0.92:5060;branch=z9hG4bKjMEHTGhvWKHZ0R2J. From: "871966760539" <sip:871966760539@10.200.0.228>;tag=SM4dtzpkDKYyCkzu. To: "8521878200" <sip:8521878200@10.200.0.228>;tag=4cdbaed0e769eb1d9b81f5252847cf64-3d33. Call-ID: nQCHB6bq42pOheks(a)10.0.0.92. CSeq: 1 CANCEL. Server: OpenSer (1.0.1 (i386/linux)). Content-Length: 0. Warning: 392 10.200.0.228:5060 "Noisy feedback tells: pid=3174 req_src_ip=10.200.0.228 req_src_port=5060 in_uri=sip:8521878200@10.200.0.228 out_uri=sip:8521878200@10.200.0.228 via_cnt==0". . ######## U 10.200.0.228:5060 -> 10.200.0.228:5060 SIP/2.0 408 Request Timeout. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.bf0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.af0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.9f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.8f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.7f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.6f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.5f0bae66.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bK5002.4f0bae66.0. Via: SIP/2.0/UDP 10.0.0.92:5060;branch=z9hG4bKjMEHTGhvWKHZ0R2J. From: "871966760539" <sip:871966760539@10.200.0.228>;tag=SM4dtzpkDKYyCkzu. To: "8521878200" <sip:8521878200@10.200.0.228>;tag=4cdbaed0e769eb1d9b81f5252847cf64-ab74. Call-ID: nQCHB6bq42pOheks(a)10.0.0.92. CSeq: 1 CANCEL. Server: OpenSer (1.0.1 (i386/linux)). Content-Length: 0. Warning: 392 10.200.0.228:5060 "Noisy feedback tells: pid=3174 req_src_ip=10.200.0.228 req_src_port=5060 in_uri=sip:8521878200@10.200.0.228 out_uri=sip:8521878200@10.200.0.228 via_cnt==0". . ########### U 10.200.0.228:5060 -> 10.200.0.228:5060 CANCEL sip:85292558811@10.200.0.228 SIP/2.0. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.edcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.ddcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.cdcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.bdcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.adcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.9dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.8dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.7dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.6dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.5dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.4dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.3dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.2dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.1dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.0dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.fccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.eccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.dccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.cccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.bccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.accf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.9ccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.8ccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.7ccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.6ccf03a7.0. Via: SIP/2.0/UDP 10.0.0.92:5060;branch=z9hG4bKlpjLoMyFjsI1BvQL. Max-Forwards: 45. User-Agent: Koncept KE10XX v4.32.14 00-09-45-0a-fc-29. From: "871966760539" <sip:871966760539@10.200.0.228>;tag=MySoSexGPE0vUXa5. To: "85292558811" <sip:85292558811@10.200.0.228>. Call-ID: 8p3FIbMUfYMXOuW3(a)10.0.0.92. Contact: <sip:871966760539@10.0.0.92:5060>. CSeq: 1 CANCEL. Content-Length: 0. . ### U 10.200.0.228:5060 -> 10.200.0.228:5060 CANCEL sip:85234163634@10.200.0.228 SIP/2.0. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Record-Route: <sip:10.200.0.228;ftag=ckRP8FNJugUqMOjy;lr=on>. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.3ffb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.2ffb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.1ffb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.0ffb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.fefb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.eefb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.defb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.cefb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.befb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.aefb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.9efb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.8efb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.7efb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.6efb2934.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf34.4efb2934.0. Via: SIP/2.0/UDP 10.0.0.92:5060;branch=z9hG4bKrmPCJR8Xm6JKY4o8. Max-Forwards: 55. User-Agent: Koncept KE10XX v4.32.14 00-09-45-0a-fc-29. From: "871966760539" <sip:871966760539@10.200.0.228>;tag=ckRP8FNJugUqMOjy. To: "85234163634" <sip:85234163634@10.200.0.228>. Call-ID: WfigvZ4YJatMKamV(a)10.0.0.92. Contact: <sip:871966760539@10.0.0.92:5060>. CSeq: 1 CANCEL. Content-Length: 0. . ######## U 10.200.0.228:5060 -> 10.200.0.228:5060 CANCEL sip:85292558811@10.200.0.228 SIP/2.0. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Record-Route: <sip:10.200.0.228;ftag=MySoSexGPE0vUXa5;lr=on>. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.cdcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.bdcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.adcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.9dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.8dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.7dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.6dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.5dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.4dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.3dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.2dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.1dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.0dcf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.fccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.eccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.dccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.cccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.bccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.accf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.9ccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.8ccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.7ccf03a7.0. Via: SIP/2.0/UDP 10.200.0.228;branch=z9hG4bKf9f4.6ccf03a7.0. Via: SIP/2.0/UDP 10.0.0.92:5060;branch=z9hG4bKlpjLoMyFjsI1BvQL. Max-Forwards: 47. User-Agent: Koncept KE10XX v4.32.14 00-09-45-0a-fc-29. From: "871966760539" <sip:871966760539@10.200.0.228>;tag=MySoSexGPE0vUXa5. To: "85292558811" <sip:85292558811@10.200.0.228>. Call-ID: 8p3FIbMUfYMXOuW3(a)10.0.0.92. Contact: <sip:871966760539@10.0.0.92:5060>. CSeq: 1 CANCEL. Content-Length: 0. .