Transfer call from Trunk to Trunk

[FG Admin]

Hi everyone,

I have a situation where I need to supply a CRM platform with a number for inbound and outbound calls. The number is provisioned to 3CX via a trunk from a physical VOIP GSM gateway. The platform uses SIP URIs, and after reading some discussions here, I managed to make it work with 3CX for inbound calls (to the SIM card) as follows:

When the inbound call reaches the GSM gateway, it is transferred to 3CX via the trunk. The trunk settings are configured to route (forward to an outside number): AAAAA. An outbound rule with the prefix "AAAAA" is set to make outbound calls on the platform's trunk.

The platform's trunk is set with the domain part of the SIP URI as the "Registrar/Server/Gateway Hostname or IP," and the Type of Authentication is set to "IP Based." In the outbound parameters, some values were adjusted to make a SIP invite with the right values in the SIP fields that the CRM platform expects (some of these include the "Remote Party ID - Calling Party" fields).

This inbound routing is working successfully.

The issue arises with outbound calls:

The CRM dialer is used to make a call to "BBBBB." This call reaches 3CX on the platform's trunk, which is configured to route to (forward to outside number): CCCCC. An outbound rule with the prefix "CCCCC" is set to make outbound calls on the GSM gateway's trunk. However, here's where the problem occurs.

According to the SIP invitation sent from 3CX to the GSM gateway, the called number is "CCCCC" and no longer "BBBBB," so the actual called number doesn't reach the gateway.

Is there any way to achieve this using a CFD or C# code? Perhaps something that uses the "ActiveConnection.ExternalParty Property," for example?

 

[edossantos_sipcaller]

The issue seems to be that the caller extension is being used as the callerNumber instead of the CFD extension.

Yes, that's how it works because the CFD app will do a blind transfer. There is no way to change this.

 

[FG Admin]

Well, I guess I will have to live with it for the time being, but since I am trying to force 3CX to be something it isn't (a switch according to you).
Do you have any recommendations for a software that can achieve what I was aiming for? I know this might be outside the forum's scope, but I would rather simplify my 3CX setup more than I have it right now (I already employed multiple weird quirks to achieve the current state that I think bad about when they come to mind).