Single DN cannot be reached from external callers

[THealey]

Forgive me, but I am brand new to this system. I am using Cisco Unified CM Administration v11.5. 

The issue I am having is that a single DN cannot be reached from external callers. DN 4005 cannot be reached getting the error "Your call cannot be completed". 4006 and similar numbers function fine, as well as internal calls to the extension. I have verified there are no other confliction DNs. Both the device and directory number are setup in the same CSS. Another DN on the same phone can be reached both internally and externally without issue. When I add the DN to a new phone the issue persists. I have deleted DN 4005 and re-created it.

Any help is appreciated.

[Roger Kallberg]

To better help you you'll need to provide some information. To start with what control protocol do you use for your voice gateway(s) and what type of connection do you use to PSTN?

The CSS set on the receiving device and on the directory number has no involvement on a call made to the directory number. What is of interest is the partition that the directory number is put into and what CSS that is used for the voice gateway in the inbound direction, it has to have visibility of the partition where the directory number lives.

[THealey]

Roger,

Thanks for replying. My control protocol is SCCP and I believe my connection to PSTN is H.323.

Your clarification regarding CSS on the receiving device is helpful. It seems that the inbound CSS for all gateways is the same. The partition of the DN is the same as other working extensions, so I assume is can see the partition.

Thanks again for your help,

[Roger Kallberg]

Can you please share the configuration of your voice gateway? If your not comfortable to post it in the open community you can PM me or look me up on Webex, what was fomerly known as Webex Teams/Cisco Spark, and send it there.

That assumption sound correct. If it's not the content of the CSS then there is something else that is at play here. Pure guess would be a translation in either the voice gateway or in CM.

Quite likely the control protocol for your voice gateway would be H.323 and the connection to PSTN would be some type of TDM circuit.

[Nithin Eluvathingal]

Most probably it could be due to an issues with 4005 extension partitions. Check if 4006 and 4005 are in same partition. Keep 4005 in partition same as 4006 and see if it works. 

[THealey]

Nithin,

Thank you for your reply. I have verified that 4005 is on the same partition as 4006 and the issue persists.

[Nithin Eluvathingal]

Are you doing any kind of translations ? 

Could you please post your gateway config and can you run DNA on the TUNK/Gateway and see the call flow.

[JFOXP]

Hey, Did you have any luck with this?

What I would do is as follows.

1 - Make sure that 4005 is nowhere else on CUCM.

2 - Check the Voice gateway to ensure there are no funky translation rules/dial peers that 4005 could use that 4006 isn't.

3 - Make a test call after you set debug isdn q931on the gateway. See if your number hits it. (Do this when its quite time of day as the output could go bonkers)

If it doesn't (Check with the carrier)

If it does hit the gateway - Provide the output and we can work from there.