CLID Displayed Differently Depending on Destination

[Scott Magee]

I have 2 separate 3CX systems running, both are OVH Cloud instances and both using TalkTalk Business SIP Trunks and running the latest version of 3CX (currently 16.0.1.273).
When I dial a mobile number or a PSTN landline number, from either system, the CLI presented is correct (as set at SIP Trunks>TTB Trunk>Caller ID> Default caller ID).
When they dial each other, the Caller ID displayed is the main Trunk Number which is not used so incorrect.
I can not find how to resolve this but don't understand why it only seems to appear incorrect on another 3CX system.
Please can you help?

 

[JohnS_3CX]

Hi Scott,

You need to see what PBX1 sends out to the provider when you make a call.

Then you need to see what PBX2 receives from the provider when the call comes in.

Now obviously your PBX will always send the same information in the same fields, but the way the provider handles the ID when ringing PSTN/mobiles might be different to the way they handle SIP-to-SIP calls on-net.

Run a couple of captures on each PBX simultaneously, and the INVITE will show you what PBX1 sent and what PBX2 received. Then have a chat with the provider to confirm that this is indeed their default behavior. I don't know if they will allow you to change the "From: User Part" to "OutboundLineID" without breaking compatibility, but that would be one way of doing it after having a chat with them.

 

[Scott Magee]

Hi JohnS_3CX,

Thanks for your reply, I've completed some captures and had a look at them and I can see that the call from PBX1, as you stated, is obviously consistently presenting the same correct information regardless of recipient, but the receiving PBX2 sees a different CLID presented once it gets there..
e.g.
[Correct_CLI]@[SIP_provider_IP]:5060 being sent by PBX
[Main_Trunk_CLI]@ngvs-mk.tipicall.net is being received

So I guess TTB/tipicall must be changing it when on-net calls are made as you suspected.

I'm awaiting a reply from TalkTalk Business.

We only used TTB as they are in the list of 3 UK providers recommended by 3CX.

Thanks
Scott