SIP URI transformation when calls to Internet

[iNikolas]

Hi all!

I have a question about SIP URI transformation when we call to anywhere in Internet. We have CUCM - Expressway-C - Expressway-E and two domains for internal and external purpose. For exaple, internal.domain and external.domain. When we call inside our network it is Ok, we use internal domain and at remote end we see that call arrive from endpoint in internal domain. But when we call anywhere outside our network we see that call arrive from endpoint with internal SIP URI - name@internal.domain. In SIP trunk configuration we enabled option to send SIP URI of origin system. Is it possible to chenge SIP URI of caller on Expressway-E? How we can change internal.domain on external.domain for external calls?

[Randy Valverde Rojas]

Hello,

There are only 2 ways to modify the source (from field) on the VCS/Expressway series, FindMe (or user policy) which normally applies for unifying various URIs under one (single number reach) so this doesn't really apply for what you are looking to do.

The other way (from the Telepresence perspective) would be with custom CPL scripts as these allow to modify the source before routing the call, that way it would show the "external" domain for outbound external calls if applied correctly on the VCS-E/Expressway-E.

http://www.cisco.com/c/dam/en/us/td/docs/telepresence/infrastructure/vcs/admin_guide/Cisco-VCS-Administrator-Guide-X8-7.pdf

Page 335 explains a bit on how to start generating these scripts. These are also customer made and usually an external call policy is recommended but the CPL can also be done.

Attached is an example of an XML, keep in mind this is not intended for you to apply it but to use as a guide.

Hope this helps.

[Patrick Sparkman]

I just came across a question from someone else that had the same issue, expressway-e-v851-change-source-uri-outgoing-call, he uses a CPL script.  There is also a CPL script that is attached that will change both the outbound and inbound domains, this is needed because if you change the domain for outbound calls, you need a corresponding rule to change the domain for inbound calls so they can match your internal addresses.