AudioCodes Mediant 4000 SBC - Relay Mode for T.30 and V.34 Faxes; V.34 Fax Relay for SG3 Fax Machines

CHAPTER15 Media
Mediant 4000 SBC | User's Manual
2. Configure the [V34FaxTransportType] parameter to [2] (Bypass).
➢ To use bypass mode for V.34 faxes, and T.38 for T.30 faxes:
1. On the Fax/Modem/CID Settings page, do the following:
● Set the 'Fax Transport Mode' parameter to T.38 Relay [FaxTransportMode = 1].
● Set the 'V.22 Modem Transport Type' parameter to Enable Bypass
[V22ModemTransportType = 2].
● Set the 'V.23 Modem Transport Type' parameter to Enable Bypass
[V23ModemTransportType = 2].
● Set the 'V.32 Modem Transport Type' parameter to Enable Bypass
[V32ModemTransportType = 2].
● Set the 'V.34 Modem Transport Type' parameter to Enable Bypass
[V34ModemTransportType = 2].
2. Configure the [V34FaxTransportType] parameter to [2] (Bypass).
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. On the Fax/Modem/CID Settings page, do the following:
● Set the 'Fax Transport Mode' parameter to T.38 Relay (FaxTransportMode = 1).
● Set the 'V.22 Modem Transport Type' parameter to Disable (V22ModemTransportType =
0).
● Set the 'V.23 Modem Transport Type' parameter to Disable (V23ModemTransportType =
0).
● Set the 'V.32 Modem Transport Type' parameter to Disable (V32ModemTransportType =
0).
● Set the 'V.34 Modem Transport Type' parameter to Disable (V34ModemTransportType =
0).
2. Configure the [V34FaxTransportType] parameter to [1] (Relay).
➢ To allow V.34 fax relay over T.38:
■ Set the 'SIP T.38 Version' parameter to Version 3 (SIPT38Version = 3).
➢ To force V.34 fax machines to use their backward compatibility with T.30 faxes and
operate in the slower T.30 mode:
■ Set the 'SIP T.38 Version' parameter to Version 0 (SIPT38Version = 0).
For SBC calls, the device forwards T.38 Version 3 transparently (as is) to the other leg
(i.e., no transcoding).
V.34 Fax Relay for SG3 Fax Machines
Super Group 3 (SG3) is a standard for fax machines that support speeds of up to 33.6 kbps through
V.34 half duplex (HD) modulation. The following procedure describes how to configure V.34 (SG3)
fax relay support based on ITU Specification T.38 version 3.
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