AudioCodes Mediant 800B User Manual page 1019

User's Manual
Parameter
det-fax-on-ans-tone
[DetFaxOnAnswerTone]
CED Transfer Mode
[CEDTransferMode]
T.38 Fax Session
t38-sess-imm-strt
[T38FaxSessionImmediateStart]
Version 7.0
61. Configuration Parameters Reference
session for fax transmission.

[0] Initiate T.38 on Preamble = (Default) The
device to which the called fax is connected
initiates a T.38 session on receiving HDLC
Preamble signal from the fax.

[1] Initiate T.38 on CED = The device to which
the called fax is connected initiates a T.38
session on receiving a CED answer tone from
the fax. This option can only be used to relay
fax signals, as the device sends T.38 Re-
INVITE on detection of any fax/modem
Answer tone (2100 Hz, amplitude modulated
2100 Hz, or 2100 Hz with phase reversals).
The modem signal fails when using T.38 for
fax relay.
Note: The parameters is applicable only if the
IsFaxUsed parameter is set to 1 (T.38 Relay) or 3
(Fax Fallback).
Defines the method for sending fax/modem CED
(answering) tones.

[0] Fax Relay or VBD = (Default) The device
transfers the CED tone in Relay mode and
starts the fax session immediately.

[1] Voice Mode or VBD = The device transfers
the CED tone in either Voice or Bypass mode
and starts the fax session on V21 preamble.

[2] RFC 4733 Blocking RTP VBD = The
device transfers the CED tone in RFC 2833.
This is applicable only to V.150.1 modem
relay and fax bypass.

[3] RFC 4733 Along with RTP VBD = The
device transfers the CED tone in RFC 2833
and bypass, in parallel. For combined V.150.1
modem relay and fax relay, use this option.
Note: The parameter is applicable only to the
Gateway application.
Enables fax transmission of T.38 "no-signal"
packets to the terminating fax machine.

[0] Disable (default)

[1] Immediate Start on Fax = Device activates
T.38 fax relay upon receipt of a re-INVITE with
T.38 only in the SDP.

[2] Immediate Start on Fax & Voice = Device
activates T.38 fax relay upon receipt of a re-
INVITE with T.38 and audio media in the SDP.
The parameter is used for transmission from fax
machines connected to the device and located
inside a NAT. Generally, the firewall blocks T.38
(and other) packets received from the WAN,
unless the device behind NAT sends at least one
IP packet from the LAN to the WAN through the
1019 Mediant 800B Gateway and E- SBC
Description