Setting up a Hamshack Hotline Trunk in 3CX PBX

I have a 3CX PBX at home I use for a few things, and I also have a Cisco SPA504g that I use with HamShack Hotline.

I have a second extension setup on the SPA504g for my 3CX system, but I figured it might be a good idea to get the 3CX system to register to HH as a trunk as well! That way I can also make and receive HH calls from my phone and the amazing 3CX application.

I applied for a new trunk line via the HH Support Center, and received it the following morning.

They provided me with three pieces of information;
User: 30027 – This is the extension number assigned to my trunk (Try calling me!)
Password: aprettygoodpasswordwashere
IAX Host:

The IAX Host is the SIP server, and should accept a SIP Register on port 5060 with the authentication info above.

In the 3CX Management Console, I went to Trunks and clicked Add SIP Trunk.

I selected Generic as the country, and Generic VoIP Provider as the provider.
The Main Trunk Number should be the extension provided above.

I filled out the info where it needs to go, and set the destination for calls to the main trunk number to go straight to my extension, so Ill get them on my mobile or PC.

This SHOULD be all that’s required!
But alas, I am not that lucky today.

The trunk is failing to register.
If we switch over to the 3CX Event Log, we can see the failed registration attempt.

Its worth noting here, that while the log shows the user as, this is merely a graphical confusion, as 10001 is the internal number assigned to the trunk by 3CX, and not the actual user that it attempts to register with. 3CX Uses the SIP User ID we entered above to register, but I am still receiving a 403 Forbidden from the (which currently resolves to server.

I thought this may be happening due to the second connection I already have from this address, the Cisco SPA504g handset, so I connected to my Unifi Controller and shutdown the PoE to the port the phone is connected to.

Once the phone went offline I tried registering again through 3CX, and this time it gives an error that the service is not available…

I have reached out to the HHOPS team to see if there is any issues currently with the server, and will update my post here when I hear back, or if I otherwise resolve the issue.


I heard back from HHOPS!

They gave a few suggestions, and I was able to get things up and running!

Rather than Generic SIP Provider I have used Asterisk as the type, and rather than 5060 for the port, I have used 4569.
It is now successfully registered and appears to be working!

To finalise, I have also setup an Outbound Rule for Hamshack Hotline, where calls to numbers with a length of 5 digits get routed out the new Hamshack Hotline trunk.