Fax Voip T.38 Modem will start in the mode of receiving G711 fax. In the case of receiving T.38 re-invite from the other side, Fax Voip T.38 Modem answers 'not supported' and continues to receive a fax in audio mode. To set this mode in VOIP Incoming Call Routing rule:
1. Check G.711 audio fax option.
2. Uncheck T.38 fax option.
3. Uncheck Detect T.38 re-invite option.
Notes