[Spce-user] My REGISTER FROM realm is different from my INVITE FROM realm. Registers are fine, invites are rejected.

[Harry Foster]

Hi all 

I’m currently evaluating SIPWise C5 CE, (using the 10.2.1 build but eventually we will decide on an LTS release) and I’ve been having trouble with an upstream peer which we send all the calls to.

The peer uses registration based trunks, which I had no problems registering to, I can set the auth realm no issue and it registers with the correct domain. However when it comes to invites originating from subscribers, it appears that we are sending the FROM domain part as the domain I configured which is an internal IP address for testing purposes. The peer won't accept anything other than a FROM comprised of: <sip:'<allowed-cli>@example.com>', of which the domain in question is a domain we have no control over.

Ideally, my intended design will be multiple customers subscribing their handsets, with each customer sending their invites to their own individual trunks. The trunks are per customer, not just a peer I can chuck everything at unfortunately.

Whilst I could set the domain to 'example.net', I won't be able to sign any certificates or use it in any official capacity. 

So I've got two questions:

1. Is this intended behaviour? Am I configuring this incorrectly? I come from a Freeswitch background, so I'm used to more an internal sip profile and external sip profile with differing realms for each.

2. Will I have to kludge a SIP header rewrite to make this work for each trunk I create?

TL;DR: My REGISTER FROM realm is different from my INVITE FROM realm. Registers are fine, invites are rejected.

All the best

Harry Foster