CME SIP Issue

ColbyG

Ok, I have a SIP trunk through Flowroute.com, and I'm having issues with calls dropping. They are dropping because I'm not ACKing their 200 messages (most of the time). Sometimes I do and everything works. I spent 45 minutes on the phone with one of their engineers, but we couldn't figure out wtf this was happening. Below are some 200 messages, the ones that say "fail" are the cases where I'm NOT sending ACKs, the ones that say "success" are cases where I DO sent ACKs. Can anyone tell me what might be causing this? I'll post whatever config you guys need as well. Thanks!

fail:
Received:
SIP/2.0 200 OK
Via: SIP/2.0/UDP 71.43.xx.xxx:5060;branch=z9hG4bK68A21C4
From: <sip:407732xxxx@flowroute.com>;tag=42933F68-1B3D
To: <sip:8003569377@flowroute.com>;tag=14c02ea8+1+81e80098+18fe8ef2
Call-ID: 5C464B76-A88D11DE-80939EE0-F74679EE@71.43.xx.xxx
CSeq: 102 INVITE
Record-Route: <sip:70.167.153.138;lr;ftag=42933F68-1B3D>
Record-Route: <sip:70.167.153.130;lr;ftag=42933F68-1B3D>
Server: DC-SIP/2.0
Contact: <sip:8003569377@65.98.237.158:5060;transport=udp>
Content-Type: application/sdp
Content-Length: 183

fail:
Received:
SIP/2.0 200 OK
Via: SIP/2.0/UDP 71.43.xx.xxx:5060;branch=z9hG4bK69E547
Record-Route: <sip:70.167.153.138;lr;ftag=42A4D4C8-341>
Record-Route: <sip:70.167.153.130;lr;ftag=42A4D4C8-341>
To: <sip:16178613962@flowroute.com>;tag=3462816387-372834
From: <sip:407732xxxx@flowroute.com>;tag=42A4D4C8-341
Call-ID: B213F63-A89011DE-80AF9EE0-F74679EE@71.43.xx.xxx
CSeq: 102 INVITE
Allow: INVITE, BYE, OPTIONS, CANCEL, ACK, REGISTER, NOTIFY, INFO, REFER, SUBSCRIBE, PRACK
Contact: <sip:16178613962@66.234.182.43:5060>
Call-Info: <sip:66.234.182.43>;method="NOTIFY;Event=telephone-event;Duration=1000"
Content-Type: application/sdp
Content-Length: 151

success:
Sent:
Received:
SIP/2.0 200 OK
Via: SIP/2.0/UDP 71.43.xx.xxx:5060;branch=z9hG4bK6A6B6A
Record-Route: <sip:70.167.153.138;lr;ftag=42AC58CC-1029>
Record-Route: <sip:70.167.153.130;lr;ftag=42AC58CC-1029>
To: <sip:16178613962@flowroute.com>;tag=3462816880-50716
From: <sip:407732xxxx@flowroute.com>;tag=42AC58CC-1029
Call-ID: 30B6B5A8-A89111DE-80BB9EE0-F74679EE@71.43.xx.xxx
CSeq: 102 INVITE
Contact: <sip:16178613962@66.234.182.43:5060>
Content-Type: application/sdp
Content-Length: 158

success:
Received:
SIP/2.0 200 OK
Via: SIP/2.0/UDP 71.43.xx.xxx:5060;branch=z9hG4bK68C1251
Record-Route: <sip:70.167.153.138;lr;ftag=42948F30-2200>
Record-Route: <sip:70.167.153.130;lr;ftag=42948F30-2200>
To: <sip:16178613962@flowroute.com>;tag=3462815321-56
From: <sip:407732xxxx@flowroute.com>;tag=42948F30-2200
Call-ID: 8F82BFB5-A88D11DE-80979EE0-F74679EE@71.43.xx.xxx
CSeq: 102 INVITE
Contact: <sip:16178613962@66.234.182.43:5060>
Content-Type: application/sdp
Content-Length: 160

Errors (debug ccsip error):
Sep 24 22:15:02.345: //-1/xxxxxxxxxxxx/SIP/Error/sipSPIMatchRespToReqTran: Failed Response check insippmh_get_resp_code

networker050184

First thing I would do is hook up wireshark and get a look at the SDP to see if there is something differing between the good calls and bad calls.

If everything is exactly the same on good and bad calls and you just do not respond sometimes try a different IOS. I've seen similar bugs to this in IOS before. Usually with SIP to H.323 interworking though.

ColbyG

Thanks brotato. I've been looking for you on Gmail to ask about this.

ColbyG

Swapped the IOS, two calls have been successful. I'll try some more, hope it keeps working!

networker050184

Cisco IOS is not the best choice for SIP IMO. At my last job we had plenty of customers run into bugs with their SIP trunk. It got to the point where we only had one approved version of IOS that we would even troubleshoot their issue with.

I haven't been online much the past couple days. I got the end of the week off to study and I've been trying to take advantage of it.