Call forward to external numbers works only in incoming number is internal

[kasper123]

I want to set up call forwarding for some of the users to an external number (their cell phones).

After I set it up it works only if the caller is calling from an extension inside the organization.

If the caller is coming from outside (through the SIP trunk) then the forwarding does not work.

The CUCM version is 8.0.3.20000-2 and the incoming/outgoing calls are coming through a SIP trunk that is directly terminated at the CUCM (no cube is used).

Does anyone have an idea why forwarding will not work for external numbers? 

[Manish Gogna]

Please make sure that the Forward Busy External or Forward No Answer External setting on the DN has a CSS assigned that contains the partition applied on the Route pattern.

HTH

Manish

[kasper123]

Hi Manish,

All settings for CSS on the Call Forward and Pickup Settings are set with a CSS that can dial cell phone numbers and as I said it works if the caller is an internal extension.

Calling Search Space Activation Policy is set: With Activating Device/Line CSS

[Leszek Wojnarski]

I think instead of guessing why it might fail, the fastest way to get the fix for this would be to download CUCM traces, accoridng to this document:

https://supportforums.cisco.com/document/126666/collecting-cucm-traces-cucm-862-tac-sr

And upload them to the forum for analyze.

One thing you might want to try is to check the check-box to enable MTP and see if that helps.

Leszek

[kasper123]

Hi Leszek,

You put me on the right track. Through the trace I noticed that the problem is with the number that is sent to the provider as a calling number.

Now I have a transformation set that sends the number 5100XXX (XXX is the local extension) as a calling number whenever a call to the outside is made by a local XXX extension.

What is going on now is that the CUCM uses the incoming caller number as an outgoing number that calls the cell phone.

So it takes the last 3 digits of the number and puts 5100 in front of them. This causes the call to fail because that number is not allowed by the sip provider.

To make things clearer let's say that:

-the external number is 1234567 and

-it calls an inside extension 234.

-The extension 234 has forwarded all calls to a cell number 079666777

So now CUCM uses the transform mask 5100XXX, takes the last 3 digits from 1234567 and sends 5100567 as the calling number instead of 5100234 and because of this the SIP provider does not allow the call. Is there a way to tell CUCM to take the last 3 digits from the local extension and not the external incoming caller number?

Regards.

[Leszek Wojnarski]

Hi, you can try changing the parameter "Calling Party Selection" on SIP trunk settings and set it to "First Redirect Number"

Leszek

[Chris.Otte]

I know this is an old post, but it's what I found when searching for the issue we are having.

Same as above, if the call originates internally the forward works, but if the call originates externally then it does not.

The calling party would receive a dial tone when calling from an external number.

The solution for me was to change the "Calling Party Selection" on SIP trunk settings to "First Redirect Number (External)"

From what I gather, our PRI provider would not allow us to send out numbers that weren't in our DID range.

Thanks!

[Corey2]

Chris, very helpful post. Only realized I had an issue with call forwarding when our secondary trunk went down, bringing down all externally forwarded calls. Changed our primary trunk to "Last Redirect Number (External)" to match our secondary trunk, and good to go! Took me a lot of digging and a troubleshooting before finding this post. Thanks again!

[ejazahmedmukhtar]

Some Service Providers don't allow calls from numbers which does'nt belong to their customer's DID range. Please see if the below post is helpful to you:

https://supportforums.cisco.com/document/74586/configure-and-troubleshoot-call-forward-pstn-using-sip-trunks

Please rate if this resolves your issue.