Fax Forwarding

[IsaacK]

I am trying to forward all calls coming in on my fax DID line to outside fax server. I tried two ways:

1. In inbound rules, route call to "forward to outside number". When attempting to call my DID the call does not get through
2. Created a dummy extension that always forwards it to outside number. The call is forwarded and I hear the fax tone, but the fax does not get through

Does anyone know how to configure this?

 

[SweetAction]

#1 is the way to do this, but can you tell me why (put PBX in verbose mode, make test call) it isn't working? Maybe it's missing an outbound rule or similar.

 

[IsaacK]

It very well may be. I didn’t create any new outbound rule. What should I do?

 

[YiannisH_3CX]

My recommendation would be to do this from the providers side if possible and forward all calls to the specific DID to your Fax service. There is no reason why you should involve 3CX in this. You are adding complexity and many things to go wrong.
My second option would be to use 302 Diversion if your provider supports it. This will completely remove 3CX from the equation.

 

[IsaacK]

Thank you for the input. Indeed, my provider VoxTelesys has a way better fax server solution. So instead of using my old fax service, I configured theirs. It is a fax to email to fax bidirectional. Let’s see if it is reliable. Test faxes went through. First faxes are in.

 

[Kevin@voxtelesys]

@IsaacK let us know how your testing goes, if needed please open a ticket with our support and we can do some more checking on the F2E logs.

 

[IsaacK]

Hi Kevin,
I eventually created a forwarding to my fax service through VoxTelesys, without involving 3CX, as suggested. I was surprised though, why it would not work on 3CX.

 

[Kevin@voxtelesys]

Could have been a formatting issue, in the event logs do you see any error for that transfer?

 

[YiannisH_3CX]

I eventually created a forwarding to my fax service through VoxTelesys, without involving 3CX, as suggested. I was surprised though, why it would not work on 3CX.

You probably need to enable re-invites in the trunk options for this to work otherwise the T38 re-invite will not be forwarded by 3CX.
When you forward a call through 3CX the PBX stays in the session and all messages pass through the PBX so when the re-invite for Fax comes back to the PBX, re-invites should be enabled.

Doing directly though is still your best bet. Enabling re-invites will affect all calls on the trunk and you might have issues with on hold music etc. Also as I mentioned this adds to the complexity and it makes things harder to troubleshoot when things go wrong as you now have an additional endpoint in the equation.

Hopefully this helps.