AudioCodes E-SBC User Manual

CHAPTER19 Coders and Profiles
Mediant 1000 Gateway & E-SBC | User's Manual
Parameter Description
Note:
■ 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 the parameter is set to 1, 2, or 3, the parameter
FaxTransportMode is ignored.
■ When the 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.
■ The corresponding global parameter is IsFaxUsed.
'CNG Detector Mode'
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.
■ [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 the preamble signal is detected by the
answering fax. Some SIP devices do not support the
detection of this fax signal on the answering fax 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 fax. However, this mode
is not recommended.
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AudioCodes E-SBC Specifications

General

Brand	AudioCodes
Model	E-SBC
Category	Gateway
Language	English