AudioCodes Mediant 500L MSBR

User's Manual 22. Coders and Profiles
Version 6.8 337 Mediant 500L MSBR
Parameter Description
Configuring Coder Groups on page 326).
Web: Fax Signaling Method
CLI: fax-sig-method
[IpProfile_IsFaxUsed]
Defines the SIP signaling method for establishing and
transmitting a fax session when the device detects a fax.
 [0] No Fax = (Default) No fax negotiation using SIP
signaling. The fax transport method is according to the
FaxTransportMode parameter.
 [1] T.38 Relay = Initiates T.38 fax relay.

[2] G.711 Transport = Initiates fax/modem using the coder
G.711 A-law/Mu-law with adaptations (see Note below).
 [3] Fax Fallback = Initiates T.38 fax relay. If the T.38
negotiation fails, the device re-initiates a fax session
using the coder G.711 A-law/Mu-law with adaptations
(see the Note below).
Notes:
 Fax adaptations (for options 2 and 3):

Echo Canceller = On

Silence Compression = Off

Echo Canceller Non-Linear Processor Mode = Off

Dynamic Jitter Buffer Minimum Delay = 40

Dynamic Jitter Buffer Optimization Factor = 13
 If the device initiates a fax session using G.711 (option 2
or 3), a 'gpmd' attribute is added to the SDP in the
following format:

For A-law: 'a=gpmd:8 vbd=yes;ecan=on'

For Mu-law: 'a=gpmd:0 vbd=yes;ecan=on'
 When this parameter is set to 1, 2, or 3, the parameter
FaxTransportMode is ignored.
 When this parameter is set to 0, T.38 might still be used
without the control protocol's involvement. To completely
disable T.38, set FaxTransportMode to a value other than
1.
 For more information on fax transport methods, see
Fax/Modem Transport Modes on page 182.
 The corresponding global parameter is IsFaxUsed.
Web: CNG Detector Mode
CLI: cng-mode
[IpProfile_CNGmode]
Enables the detection of the fax calling tone (CNG) and
defines the detection method.
 [0] Disable = (Default) The originating fax does not detect
CNG; the device passes the CNG signal transparently to
the remote side.
 [1] Relay = The originating fax detects CNG. The device
sends CNG packets to the remote side according to T.38
(if IsFaxUsed is set to 1) and the fax session is started. A
SIP Re-INVITE message is not sent and the fax session
starts by the terminating fax. This option is useful, for
example, when the originating fax 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 fax). To also send a Re-INVITE
message upon detection of a fax CNG tone in this mode,
set the parameter FaxCNGMode to 1 or 2.
 [2] Event Only = The originating fax detects CNG and a
fax session is started by the originating fax, using the Re-
INVITE message. Typically, T.38 fax session starts when