VG204XM FAX problem after upgrade IOS to advipservicesk9-mz.159-3M6

[dsobrinho]

Hi guys,

Have any of you experienced problems with fax sending and receiving after an IOS upgrade? I had a recent case where everything was working and after this update the service stopped working. I do know if this IOS version have bugs presenting.

FAX->VG204XM->SIP TK->CUCM11.5.x->ISR4331->T1->PSTN

So the CUCM was sending Re-INVITE with T.38 caps so the below configuration was suggested:

fax protocol t38 nse ls-redundancy 0 hs-redundancy 0 fallback pass-through g711ulaw
fax-relay ecm disable
fax-relay sg3-to-g3

In the logs collected after the error 488 sent a Re-invite was received with G711alaw to sent a fax over RTP
Failure in media negotiation -- Sending 488 response

[Nithin Eluvathingal]

In this case i suggest revert back to old version and re-verify if FAX works properly. If it works fine then probably it could be bug on the version.

2.12.0.0