[cisco-voip] Cisco ATA Fax Confusion

[Rhodium]

Hi All,

Hoping someone would shed some light on what I considered an immutable truth that cannot be changed.

I was under the impression that a Cisco ATA 186 running SCCP does NOT support fax protocol based "pass-through" only supporting nse fax "passthrough".

The reason why I am asking is that I am troubleshooting a fax issue where an ATA sending to a VG224 (SCCP) is not able to send multiple pages. I am putting this down to the speed negotiated for the fax tranmission so need to drop it to 9600bps or less but the VG224 config is setup for protocol-based pass-through:

!
voice service voip 
 fax protocol t38 nse ls-redundancy 0 hs-redundancy 0 fallback pass-through g711ulaw
!
!
dial-peer voice 2452 pots
 service stcapp
 port 2/11
!


Just want to clarify that point as I am sure I am missing an update from Cisco as regards added functionality to the firmwares on ATA or something similar as I can't explain how the faxes work in the first place between these supposedly "incompatible" devices from the perspective of protocols.

Regards,

Jason