AudioCodes Mediapack mp-11x, User Manual

Page: 330 / 390

SIP User's Manual 330 Document #: LTRT-65409
MediaPack Series
7.2.3 Supporting V.34 Faxes
Unlike T.30 fax machines, V.34 fax machines have no relay standard to transmit the data
over IP to the remote side. Therefore, the gateway provides the following operation modes
for transporting V.34 fax data over the IP:
„ Using bypass mechanism for V.34 fax transmission (refer to 'Using Bypass
Mechanism for V.34 Fax Transmission' on page
330 )
„ Using relay mode, i.e., fallback to T.38 (refer to 'Using Relay mode for both T.30 and
V.34 faxes' on page
330 )
Note:
The CNG detector is disabled (CNGDetectorMode = 0) in all the following
examples.
7.2.3.1 Using Bypass Mechanism for V.34 Fax Transmission
In this proprietary scenario, the gateway uses bypass (or NSE) mode to transmit V.34
faxes, enabling the full utilization of its speed.
Configure the following parameters to use bypass mode for both T.30 and V.34 faxes:
„ FaxTransportMode = 2 (Bypass)
„ V34ModemTransportType = 2 (Modem bypass)
„ V32ModemTransportType = 2
„ V23ModemTransportType = 2
„
V22ModemTransportType = 2
Configure the following parameters to use bypass mode for V.34 faxes and T.38 for T.30
faxes:
„ FaxTransportMode = 1 (Relay)
„
V34ModemTransportType = 2 (Modem bypass)
„ V32ModemTransportType = 2
„
V23ModemTransportType = 2
„ V22ModemTransportType = 2
7.2.3.2 Using Relay mode for both T.30 and V.34 faxes
In this scenario, V.34 fax machines are forced to use their backward compatibility with T.30
faxes and operate in the slower T.30 mode.
Use the following parameters to use T.38 mode for both V.34 faxes and T.30 faxes:
„ FaxTransportMode = 1 (Relay)
„ V34ModemTransportType = 0 (Transparent)
„ V32ModemTransportType = 0