Fax Extension with Seperate SIP Trunk Question

[JDH201]

So, I'm looking at adding fax extensions with fax machines attached to ATAs to my environment to save some $. My main SIP provider does not officially support T38 so I was looking at adding a second SIP trunk from a provider that does T38. In my testing with their demo trunk I have no issue with the inbound call getting connected to the fax extension and delivering to the ATA, but my outbound fax calls get routed through my primary SIP trunk. I have tried creating an outbound rules with my fax extension, but that doesn't help. I also tried creating a group with all of my non fax extensions and telling my main rules to service that group which doesn't include my fax extension, but that didn't change it either.

So how do you get it to use the T38 SIP trunk?

 

[cobaltit]

You make an outbound rule. The fact that you did it and it didn't work doesn't mean that's not the way to do it, rather that you aren't doing it the right way. Outbound rules are processed top down so you need to make sure the rule restricted to the fax extension or group is before other rules that may otherwise match.

 

[JDH201]

Thank you. Being a 20 year firewall jockey I should have realized that. I adjusted my outbound rules and will test tomorrow.

 

[eddv123]

Quick FYI, if your provider did not support T.38 Faxing then you could of switched to G.711 Pass-through and had no need for an additional trunk. Or just use a provider who supports T.38 from day 1 obviously.