How to connect a 3CX PBX to 2talk

Follow this quick start guide to connect a 3CX PBX to 2talk.

2talk Portal Instructions

Choose between a Peering Trunk or a Registered Trunk. Once selected follow the instructions for the chosen method.

Configuring a peering SIP trunk

Configure an account peering trunk, or set peering IPs in the number manager, in the 2talk portal.

Configuring a registered SIP trunk

Pilot:

Under "Outbound Calls" -> "Outbound Trunking" tick the "Enable Outbound Trunking" box.

DDIs:

Under "Inbound Calls" -> "Forwarding and Trunking" set "Send inbound calls to registered number" to the pilot and tick the "Preserve DDI" box.

3CX Web UI instructions

Configuring a peering SIP trunk

From the 3CX Management Console, select “SIP Trunks” > “Add SIP Trunk”.
Under country select "New Zealand", under provider select “2talk”.
For Main trunk number input the pilot number for your trunk as configured in the 2talk portal.

Configuring a registered SIP trunk

From the 3CX Management Console, select “SIP Trunks” > “Add SIP Trunk”.
Under country select "Generic", under provider select “Generic VoIP Provider”.
In the new trunk settings input the registrar domain you created on sign up into both "Registrar" and "Outbound Proxy".
Untick "Auto Discovery" and input "5060" in the boxes prefixing both settings.
Under "Type of Authentication" ensure "Register/Account based" is selected.
Under "Authentication ID" input the pilot number in NSN+0 format, e.g. 0xxxxxxxx.
Under "Authentication Password" input the password you assigned the pilot in the portal.
Set "Number of Simultaneous Calls" to your preference.
Set the inbound routing of the pilot number to your preference.

Configuring outbound CLI

Under the SIP Trunk settings "Caller ID" tab set the "Outbound Caller ID" to the pilot number in NSN+0 format, e.g. 0xxxxxxxx.
For a registered SIP trunk the pilot number should be the same as the "Authentication" ID from "Configuring a registered SIP trunk", for a peering SIP trunk this is the "Main trunk number" from "Configuring a peering SIP trunk".

For registered trunks set "From: User Part" to "AuthID" under the "Outbound Parameters" tab.
Set "P-Asserted Identity : User Part" to "OriginatorCallerID" under the "Outbound Parameters" tab .
For each extension ensure the preferred account phone number is configured under "Location → Extensions → Extension → General (tab) → User Information (section) → Outbound Caller ID".

Configuring outbound CLI - A party passthrough

Some diverted call scenarios from 3cx do not insert the expected headers. This fails 2talks CLI whitelisting requirements for A party passthrough on a transferred or forwarded call. Overstamping will need to be requested via a ticket to permit the trunk to do A party passthrough in these scenarios.

Inbound and Outbound routing configuration:

Set Inbound and Outbound rules as described by 3CX to match your preference -
https://www.3cx.com/docs/manual/inbound-did-call-routing/
https://www.3cx.com/blog/voip-howto/outbound-rules-a-complete-example/

https://www.3cx.com/docs/sip-trunk-outbound-calls/