AudioCodes Mediant 2600 - Fax; Modem Transparent Mode; RFC 2833 ANS Report Upon Fax;Modem Detection

User's Manual 164 Document #: LTRT-42060
Mediant 2600 E-SBC
14.2.2.7 Fax / Modem Transparent Mode
In this mode, fax and modem signals are transferred using the current voice coder without
notifications to the user and without automatic adaptations. It's possible to use Profiles (see
''Coders and Profiles'' on page 293) to apply certain adaptations to the channel used for fax
/ modem. For example, to use the coder G.711, to set the jitter buffer optimization factor to
13, and to enable echo cancellation for fax and disable it for modem.
 To configure fax / modem transparent mode:
1. In the SIP General Parameters page (Configuration tab > VoIP menu > SIP
Definitions > General Parameters), set the 'Fax Signaling Method' parameter to No
Fax (IsFaxUsed = 0).
2. In the Fax/Modem/CID Settings page, do the following:
a. Set the 'Fax Transport Mode' parameter to Disable (FaxTransportMode = 0).
b. Set the 'V.21 Modem Transport Type' parameter to Disable
(V21ModemTransportType = 0).
c. Set the 'V.22 Modem Transport Type' parameter to Disable
(V22ModemTransportType = 0).
d. Set the 'V.23 Modem Transport Type' parameter to Disable
(V23ModemTransportType = 0).
e. Set the 'V.32 Modem Transport Type' parameter to Disable
(V32ModemTransportType = 0).
f. Set the 'V.34 Modem Transport Type' parameter to Disable
(V34ModemTransportType = 0).
3. Set the ini file parameter, BellModemTransportType to 0 (transparent mode).
4. Configure the following optional parameters:
a. Coders table - (Configuration tab > VoIP menu > Coders and Profiles >
Coders).
b. 'Dynamic Jitter Buffer Optimization Factor' (DJBufOptFactor) - RTP/RTCP
Settings page (Configuration tab > VoIP menu > Media > RTP/RTCP Settings).
c. 'Echo Canceller' (EnableEchoCanceller) - Voice Settings page.
Note:
This mode can be used for fax, but is not recommended for modem
transmission. Instead, use the Bypass (see ''Fax/Modem Bypass Mode'' on page 161)
or Transparent with Events modes (see ''
Fax / Modem Transparent with Events
Mode'' on page 163) for modem.
14.2.2.8 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. This 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. In the SIP General Parameters page (Configuration tab > VoIP menu > SIP
Definitions > General Parameters), set the 'Fax Signaling Method' parameter to No
Fax or Fax Fallback (IsFaxUsed = 0 or 3).
2. In the Fax/Modem/CID Settings page, do the following:
a. Set the 'Fax Transport Mode' parameter to Bypass (FaxTransportMode = 2).