Patton 4112S for fax operation via SBC on 3CX Hosted (by 3CX) - SIP / 2.0 488 Not Acceptable Here

[Smart IT KUSEL]

Good day everybody,

In a 3CX project we have problems with the connection of a Patton 4112S for faxing via Canon MFP printer.
A 3CX professional may be able to help here - we are currently building our 5th project ourselves.

Set up:
3CX system in 3CX cloud
SBC local
Patton 4112S Locally on the same subnet as SBC
Canon MFP Fax to Patton FXO
Provider / SIP trunk = Easybell Germany (has T38 support)

Config according to instructions 3CX (T.38 / Mixed Mode)
Fax extensions (880/881 created)
Fax extensions are also registered
Firmware Patton up to date
3CX up to date

Situation:
Outgoing "conversation" is established but aborted after 2 seconds
LOG Error: SIP / 2.0 488 Not Acceptable Here

Files:
3CX LOG
Patton Config
(username and domain replaced)

Thanks for your help

 

[YiannisH_3CX]

Hi @Smart IT KUSEL

From what i see from the logs the call is established but since there is no re-invite for T38 from the provider the Patton device sends a re-invite for T38 which is met with a 488 Not Acceptable Here.
That could be Easybell of the upstream provider rejecting the call. Try switching your device to G711 and see if that helps