Nortel VoIP Gateway, Configuration Manual, Page: 206 / 220

206 Fax/Modem Settings
P0606298 02
Supporting V.34 Faxes
V.34 fax machine support is available only in bypass mode (fax relay is not supported) when the
channel is configured in one of the configurations described below:
• FaxTransportMode = 2 (Bypass)
• V34ModemTransportType = 2 (Modem bypass)
• V32ModemTransportType = 2
• V23ModemTransportType = 2
• V22ModemTransportType = 2
• V21ModemTransportType = 2
In this configuration both T.30 and V.34 faxes will work in Bypass mode
Or
• FaxTransportMode = 1 (Relay)
• V34ModemTransportType = 2 (Modem bypass)
• V32ModemTransportType = 2
• V23ModemTransportType = 2
• V22ModemTransportType = 2
• V21ModemTransportType = 2
In this configuration T.30 Fax uses Relay mode (T.38) while V.34 Fax uses Bypass mode.
In order to use V.34 fax in Relay mode (T.38), you must configure:
• FaxTransportMode = 1 (Relay)
• V34ModemTransportType = 0 (Transparent)
• V32ModemTransportType = 0
• V23ModemTransportType = 0
• V22ModemTransportType = 0
• V21ModemTransportType = 0
This configuration forces the V.34 fax machine to work in T.30 mode.