SIP FAX over SBC with no Session Managers?

[RedTech443]

Has anyone ever done a SBC config with SIP Fax machines and no session managers? I am looking at a request to integrate a SBC 10.x with 3 fax machines, there is no Session Manager, System Manager, communication manager involved just a SBC, SIP provider and 3 fax machines, I am not sure of the config or might be overthinking it. I could not find any documentation on this setup in particular.

 

[G van Hamburg]

You should ask the Vendor of the FAX machine and/or the SIP provider if that is possible. Some SIP providers offer a sort of 'direct registration' of devices.

Freelance Certified Avaya Aura Engineer

 

[avayaguy23]

Yes. We have Biscom fax connecting in directly to the Sonus SBC. It’s not connected to our pbx in any way.

 

[kyle555]

It's fairly straightforward. You'd have 1 trunk server and 3 call servers.

Follow the SBC setup for any SIP trunk vendor to CM

Replace the SM IP with the fax server

build the config 3 times and in the endpoint flows you'll have an inbound one from the trunk to each of the 3 fax servers.
Those 3 matches will line up to a URI group for the incoming DIDs specific to those machines.

Otherwise you just have to manage the interworking and codecs, but the fax servers will likely be going out T38 with G711 fallback anyway.

You might need to interwork T38 from Biscom to G711 to the carrier if the Biscom is set for T38 only and the carrier might only do G711 in certain circumstances.

I come from a carrier world and we'll do T38 for you if it's negotiated end to end. But if you're calling on your SIP trunk with me to a number on another carrier that I link up to through SIP as well and the far end has a plain old G711 media offer, I'm not doing the T38 to G711 for you. You might need the SBC to that. But if you're replacing a Sonus, check the configs there. You just need to replace it, right?

 

[RedTech443]

Thanks Kyle55, this is what I expected to do anyway to some degree. I am going to try this next week.