AudioCodes MediaPack Series MP-11x

User's Manual 152 Document #: LTRT-65417
MP-11x & MP-124
13.2.3 V.34 Fax Support
V.34 fax machines can transmit data over IP to the remote side using various methods.
The device supports the following modes for transporting V.34 fax data over IP:

Bypass mechanism for V.34 fax transmission (see 'Bypass Mechanism for V.34 Fax
Transmission' on page 152)

T38 Version 0 relay mode, i.e., fallback to T.38 (see 'Relay Mode for T.30 and V.34
Faxes' on page 152)
Note: The CNG detector is disabled in all the subsequent examples. To disable the
CNG detector, set the 'CNG Detector Mode' parameter (CNGDetectorMode)
to Disable.
13.2.3.1 Bypass Mechanism for V.34 Fax Transmission
In this proprietary scenario, the device uses bypass (or NSE) mode to transmit V.34 faxes,
enabling the full utilization of its speed.
 To use bypass mode for T.30 and V.34 faxes:
1. In the Fax/Modem/CID Settings page, do the following:
a. Set the 'Fax Transport Mode' parameter to Bypass (FaxTransportMode = 2).
b. Set the 'V.22 Modem Transport Type' parameter to Enable Bypass
(V22ModemTransportType = 2).
c. Set the 'V.23 Modem Transport Type' parameter to Enable Bypass
(V23ModemTransportType = 2).
d. Set the 'V.32 Modem Transport Type' parameter to Enable Bypass
(V32ModemTransportType = 2).
e. Set the 'V.34 Modem Transport Type' parameter to Enable Bypass
(V34ModemTransportType = 2).
 To use bypass mode for V.34 faxes, and T.38 for T.30 faxes:
1. In the Fax/Modem/CID Settings page, do the following:
a. Set the 'Fax Transport Mode' parameter to Relay (FaxTransportMode = 1).
b. Set the 'V.22 Modem Transport Type' parameter to Enable Bypass
(V22ModemTransportType = 2).
c. Set the 'V.23 Modem Transport Type' parameter to Enable Bypass
(V23ModemTransportType = 2).
d. Set the 'V.32 Modem Transport Type' parameter to Enable Bypass
(V32ModemTransportType = 2).
e. Set the 'V.34 Modem Transport Type' parameter to Enable Bypass
(V34ModemTransportType = 2).
13.2.3.2 Relay Mode for 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.
 To use T.38 mode for V.34 and T.30 faxes:
1. In the Fax/Modem/CID Settings page, do the following:
a. Set the 'Fax Transport Mode' parameter to Relay (FaxTransportMode = 1).