Posted by: Mudassir Ali | January 26, 2012

Troubleshooting Callmanager Issues : MGCP & H323

Troubleshooting Callmanager Issues : MGCP & H323

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Few of my notes:
1. Make sure voice gateway hostname is same in CUCM and Voice gateway.
2. MGCP gateway should show registered in CUCM
3. When selecting ports in CUCM, do a show diag in voice gateway to know your voice modules.
4. Media resources name should match both in CUCM and Voice gateway
5. H323 gateway will not show registered in CUCM
6. One way to verify if H323 gateway is talking to CUCM or not is to check your media resources registration status.
7. Always reset the voice gateway in CUCM, once you update configuration in Voice gateway.
8. You can configure MGCP gateway in CUCM, but still use it as H323 gateway by not putting the call-agent command.
9. Given a choice go with H323 gateway, as you will have good control on call legs.
10. When troubleshooting go back to basics and start from physical layer.

MGCP IOS Gateway (San Jose) Interactive Voice Network Configuration Example This is a good interactive document about CUCM, Unity & GW configuration
Cisco IOS MGCP and Related Protocols Configuration Guide, Release 12.4T (need partner level access)
Configuring the Cisco IOS MGCP Gateway
Configure MGCP Gateway and FXO/FXS Ports on a Cisco CallManager Server
Verify and Troubleshoot the Cisco IOS MGCP Gateway
MGCP Gateway Registration Failure with Cisco CallManager
Youtube Video:

MGCP Status:
show ccm-manager àDisplays a list of CUCM servers and their current status and availability
show mgcp endpoint à Displays information for endpoints that are controlled using MGCP
show mgcp connections à Displays information for active connections that are controlled using MGCP.
show mgcp statistics à Displays MGCP statistics regarding received and transmitted network messages
show mgcp srtp à Displays information for active SRTP connections controlled using MGCP
Cisco IOS Voice Troubleshooting and Monitoring — H.323 Gateway Troubleshooting
Troubleshooting Cisco IOS Voice Overview
Debug Command Output on Cisco IOS Voice Gateways
Filtering Troubleshooting Output
Cisco VoIP Internal Error Codes
Troubleshooting Cisco IOS Voice Telephony
Troubleshooting Cisco IOS Voice Protocols
Troubleshooting Cisco IOS Telephony Applications
Monitoring the Cisco IOS Voice Network
Cause Codes and Debug Values


H323 Status:
These commands are to verify digits sent and received on a POTS call leg:
show dialplan number
debug vtsp session
debug vpm signal
debug mgcp state
These commands are to verify that call setup on a VoIP call leg:
debug voice ccapi inout
debug voip dialpeer inout
debug cch323 h225
debug h225 q931

SIP Status:
show sip-ua status
show sip statistics
show sip status
debug ccsip message
Refer to my previous blog All About MGCP


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