Having a hard time finding documentation to back up what I am seeing in one customers environment regarding inbound fax.
Simple Topology:
Fax - ???? - Telco - PRI - Gateway - SIP - CUCM - SCCP - VG310 - Fax
Both the Gateway and the VG310 were (incorrectly) set to: fax protocol t38 ls-redundancy 0 hs-redundancy 0 fallback none
So my question here is: despite the expected 488 to the re-invite to do t38 (standards based, not SCCP supported), why was the fax able to complete when having fallback set to none? I observed the initial g711ulaw channels that were open weren't actually closed, so I assume that is what was being used. Is this expected behaviour? No second re-invite for fallback was seen.
