3CX and SIP trunk on Broadsoft platform, SIP 404 error

[engelsman]

I try to setup a VOIP trunk with 3CX to a Broadsoft platform. I got the following data from my VOIP provider:

- Group Domain
- User ID (Line ID)
- Authentication ID
- Authentication Password
- Proxy server I.P. address.

I use a general VOIP provider and enter the following Data:

- SIP server hostname or I.P. = <Group Domain>
- SIP server port 5060
- Outbound hostname or I.P. = <Proxy server I.P. address>
- Outbound proxy port = 5060
- External number = <User ID (Line ID)>
- Authentication ID= <Authentication ID>
- Authentication Password = <Authentication Password>

This does not work, I get a SIP 404 error (Not found)

I tried to use the trunk with a X-Lite softphone and entered the following data:

User Details:
- User ID = <User ID (Line ID)>
- Domain = <Group Domain>
- Password = <Authentication Password>
- Authorization name = <Authentication ID>

Domain Proxy:
- Register with domain an receive calls, enabled
- Send outbound via Proxy, Address: <Proxy server I.P. address>.

With this setup I get the VOIP account for the Trunk succesfully registred.

Why is this not working with 3CX Generic VOIP Provider?