CLI passthrough - fwd to mobile - BT HSIPT

[Dunblue]

Hi,

We are using BT Wholesale SIP (BT HSIPT) trying to get CLI passthrough working for calls forwarded to mobile/external number. I have read the numerous threads about this subject but have not found anything relating specifically to this SIP provider.

To confirm:

1. Clip no screening is supported
2. CLI passthrough is supported and enabled on the trunk
3. I have tried changing the various outbound parameters to "OriginatorCallerID"

From : Display Name
From : User Part
Remote Party ID - Calling Party : User Part
P-Asserted Identity : User Part

The above have been tried in every possible configuration.. The result is that all calls to the SIP will fail

So I sent a pcap to BT who responded with the following

having retraced the call I can see that you are getting a 404 user not found due to the PBX not be configured correctly. directly in relation to the number in the "Display Info part" of the PAI header. To: From: "number_redacted";tag=b78c3b0d Call-ID: HreSYSk1pfRf9LbfLsGCCQ.. CSeq: 1 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE, UPDATE Content-Type: application/sdp Supported: replaces, timer User-Agent: 3CXPhoneSystem 18.0.3.461 (461) P-Asserted-Identity: "44number_redacted" Remote-Party-ID: ;party=calling Content-Length: 314 it needed to go in the actual user part, i.e. the bit before the @ sign this is causing the rooting problems you describe. what you are requesting is a level 4 CLI and our platform supports a level 5 CLI pass through. for further configuration support on the PBX you should consult your provider

Unfortunately this is beyond the scope of my knowledge or understanding.

Can anyone advise or have experience with this provider?

 

[YiannisH_3CX]

Hi @Dunblue

Are you using Wholesale or BT SIP-T Trunk because those 2 are different products? Is it IP based or registration based?

 

[Dunblue]

Hi @Dunblue

Are you using Wholesale or BT SIP-T Trunk because those 2 are different products? Is it IP based or registration based?

Wholesale - registration based

 

[YiannisH_3CX]

Have you read our user guide? There is a specific section on how to configure the trunk for CNS.

 

[Dunblue]

If I change the From : User Part to "OriginatorCallerID" as per those instructions, all calls fail. I did describe this in the OP.

 

[leejor]

It would be helpful to confirm that the calls are failing because the number sent is in an unacceptable format, or another reason. I recall that in the past, some types of forwarded calls were passing on the forwarding extensions number, rather than the originator. As a test, have you tried setting up the ring my mobile option on the extension, to see if this works? You might also use the 3CX Activity Log (verbose) to try to identify the outgoing caller ID being sent for these calls.

 

[YiannisH_3CX]

Make sure that BT has enabled Class 5 CLI for your trunk and also make sure that you have replaced the main trunk number with a trunk DID and have removed the pilot number from there.
Like BT mentioned to you in your original post you are requesting a level 4 CLI but they support level 5.

Also I am not really sure you followed the guide since I see wrong SIP headers in the example you posted. I would start over by following the guide.