Debugging VoIP on Cisco Routers

Debugging VoIP on Cisco Routers

Just a basic collection of debugs that may be useful to run when troubleshooting VoIP issues on Cisco Routers.
As per all debugs, enabling debugs on routers can cause CPU overload causing the unit to become unresponsive.  Enable debugs carefully on busy systems.

General Dialpeer / Call Flow

These debugs will give you a call flow including pattern matching on dialpeer's and which was the ingress and egress dial peers:

• debug voip dialpeer inout
• debug voip ccapi inout

H323 Useful Debugs

For a deeper look at H323 setups and call flows:

• debug cch323 h225
• debug h245 asn1
• debug cch323 session
• debug cch323 error

SIP useful debugs

• debug ccsip messages
• debug ccsip ?

Other Notes

• If you're running a newer version of IOS make sure that your Voice service config is allowing traffic through from your remote ip's.  Saw an issue where H323 wasn't showing any debug traffic when a call was being sent through.  Issue was an with voice service not accepting connections because the remote ip wasn't in the list of allowed IP's.
• Dialpeer matching logic useful doc: http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/voice_troubleshooting/old/vts_appa.html

• An awesome debug doc from cisco: https://supportforums.cisco.com/docs/DOC-16310