Single Extension Unable to Dial 866 Numbers

[kmartin3260]

Hello, everyone!

We are experiencing a peculiar issue where a single extension is unable to dial out to any 866 number - can dial out to other toll free numbers. The user receives a “call cannot be completed as dialed” message from the carrier. Here’s a summary of the situation:

•Extension Configuration: The problematic extension has the same Calling Search Space (CSS) and other configurations as all other extensions in the organization.

•Other Extensions: All other extensions can dial out to 866 numbers without a problem.

•Gateway/Route List: When we change the Gateway/Route List in the Route Pattern to another gateway, the problematic extension can successfully dial out to 866 numbers. Meanwhile, all other extensions continue to dial out to 866 numbers without any issues.

Has anyone encountered a similar issue or can suggest troubleshooting steps to resolve this problem? Your help and suggestions would be greatly appreciated.

This is my first post here, so please feel free to let me know if I left out any important information. 

Client is on CUCM Ver. 12.5.1.18901-1

[chandra.mishra]

@kmartin3260  What is the call flow . before changing GW/RL to New GW/RL both have the same provider? As per my experience affected extension can be blocked by Provider . What's failure Reason are u getting on affected VGW log.. did u look the debugs?

Try to remap the extension, took logs from vgw and check from where issue came

[Nithin Eluvathingal]

Firstly, the message “call cannot be completed as dialed” is generated by the CUCM, not the provider. This message is played when the CUCM cannot handle the call. You mentioned that both working and non-working extensions have the same CSS. Could you please check the CSS assigned at the phone level for both these extensions? I’m asking this because if there’s a CSS at the extension level and a different one at the phone level, the phone CSS takes precedence.

Have you debugged the gateway? If the calls are functioning when you change the gateway, then the issue lies with the gateway. Debugging the call will provide more information.

Could you share the debugs of the gateway? If it’s a SIP gateway, use “debug CCSIP messages”. If it’s a PRI, use “debug isdn q931”. also share, “debug voice ccapi inout”.

[Maren Mahoney]

It might be worthwhile to examine a working phone/target number and a non-working phone/target number using the Dialed Number Analyzer. Saving both outputs and comparing them might show what the difference is.

I agree with @Nithin Eluvathingal - The first thing I'd check is that both the Line CSS and Device CSS are the same on the non-working phone as the working phone. 

If they are the same, then the next step would be to collect a debug on the gateway/CUBE for a working and non-working call to see if the non-working call is reaching the gateway. If it is not then the issue is 100% a CUCM issue. If it is reaching the gateway, then it is likely a gateway issue.

Maren