SIP User's Manual 428 Document #: LTRT-12801
MP-500 MSBG
Parameter Description
Web/EMS: CNG Detector Mode
[CNGDetectorMode]
Determines whether the device detects the fax Calling tone
(CNG).
 [0] Disable = The originating device doesn’t detect CNG;
the CNG signal passes transparently to the remote side
(default).
 [1] Relay = CNG is detected on the originating side. CNG
packets are sent to the remote side according to T.38 (if
IsFaxUsed = 1) and the fax session is started. A Re-
INVITE message isn’t sent and the fax session starts by
the terminating device. This option is useful, for example,
when the originating device is located behind a firewall that
blocks incoming T.38 packets on ports that have not yet
received T.38 packets from the internal network (i.e.,
originating device). To also send a SIP Re-INVITE
message upon detection of a fax CNG tone in this mode,
set the parameter FaxCNGMode to 1.
 [2] Events Only = CNG is detected on the originating side
and a fax session is started by the originating side using
the Re-INVITE message. Usually, T.38 fax session starts
when the ‘preamble’ signal is detected by the answering
side. Some SIP devices don’t support the detection of this
fax signal on the answering side and thus, in these cases it
is possible to configure the device to start the T.38 fax
session when the CNG tone is detected by the originating
side. However, this mode is not recommended.
Web: Fax/Modem Bypass Packing
Factor
EMS: Packetization Period
[FaxModemBypassM]
Number of (20 msec) coder payloads that are used to
generate a fax/modem bypass packet.
The valid range is 1, 2, or 3 coder payloads. The default value
is 1 coder payload.
[FaxModemNTEMode]
Determines whether the device sends RFC 2833 ANS/ANSam
events upon detection of fax and/or modem answer tones (i.e.,
CED tone).
 [0] = Disabled (default).
 [1] = Enabled.
Note: This parameter is applicable only when the fax or
modem transport type is set to bypass or Transparent-with-
Events.
Web/EMS: Fax Bypass Payload
Type
[FaxBypassPayloadType]
Determines the fax bypass RTP dynamic payload type.
The valid range is 96 to 120. The default value is 102.
EMS: Modem Bypass Payload Type
[ModemBypassPayloadType]
Modem Bypass dynamic payload type.
The range is 0-127. The default value is 103.
EMS: Relay Volume (dBm)
[FaxModemRelayVolume]
Determines the fax gain control.
The range -18 to -3 corresponds to -18 dBm to -3 dBm in 1-dB
steps. The default is -6 dBm fax gain control.
Web/EMS: Fax Bypass Output Gain
[FaxBypassOutputGain]
Defines the fax bypass output gain control.
The range is -31 to +31 dB, in 1-dB steps. The default is 0
(i.e., no gain).