AudioCodes Mediant 4000 SBC, User Manual

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CHAPTER 15 Media
Mediant 4000 SBC | User's Manual
RFC 2833 ANS Report upon Fax/Modem Detection
The device (terminator gateway) sends RFC 2833 ANS/ANSam events upon detection of fax
and/or modem answer tones (i.e., CED tone). This causes the originator to switch to fax/modem.
The parameter is applicable only when the fax or modem transport type is set to bypass,
Transparent-with-Events, V.152 VBD, or G.711 transport. When the device is located on the
originator side, it ignores these RFC 2833 events.
➢
To configure RFC 2833 ANS Report upon fax/modem detection:
1. On the Fax/Modem/CID Settings page, do the following:
● Set the 'Fax Transport Mode' parameter to Bypass (FaxTransportMode = 2).
● Set the 'V.xx Modem Transport Type' parameters to Enable Bypass
(VxxModemTransportType = 2).
2. Configure the [FaxModemNTEMode] parameter to [1] (enables this feature).
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 )
■ T.38 Version 0 relay mode, i.e., fallback to T.38 (see Relay Mode for T.30 and V.34 Faxes )
To configure whether to pass V.34 over T.38 fax relay, or use Bypass over the High Bit Rate coder
(e.g. PCM A-Law), use the 'V.34 Fax Transport Type' parameter (V34FaxTransportType).
You can use the 'SIP T.38 Version' parameter (SIPT38Version) to configure one of the following:
■ Pass V.34 over T.38 fax relay using bit rates of up to 33,600 bps ('SIP T.38 Version' is set to
Version 3).
■ Use Fax-over-T.38 fallback to T.30, using up to 14,400 bps ('SIP T.38 Version' is set to
Version 0).
● The CNG detector is disabled in all the subsequent examples. To disable the CNG
detector, set the 'CNG Detector Mode' parameter (CNGDetectorMode) to
Disable .
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. On the Fax/Modem/CID Settings page, do the following:
● Set the 'Fax Transport Mode' parameter to Bypass [FaxTransportMode = 2].
● 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].
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