T38 Fax with Re-invite + G711 Fax Mode (T38+R,G711)

Fax Voip T.38 Modem will start in the mode of sending T.38 fax (sends T.38 re-invite to the other side). With the positive response from the other side, Fax Voip T.38 Modem sends T.38 fax. If the other party answers 'not supported', Fax Voip T.38 Modem switches to G711 fax and sends the fax as audio. To set this mode in VOIP Outgoing Call Routing rule:

1.     Check G.711 audio fax option.

2.     Check T.38 fax option.

3.     Check Send T.38 re-invite option.

Notes

• It is recommended to use this mode only if the VoIP provider offers support for T.38, but for some reason does not generate T.38-reinvite, when the remote fax machine answers.
• When using this mode CNG tone may not be transferred, depending on the capabilities of SIP/H.323 network.
• Not recommended to use this mode to send a fax as G711 fax, because other side is not always able to answer 'not supported'. In the described situation switch to G711 fax will not happen and fax will not be transferred.
• It is recommended to use this mode, if dummy G.729* codec is used, to ensure CNG tone generation.