AudioCodes Mediant 500 MSBR, Руководство пользователя

Страница: 437 / 1248

Version 7.2 437 Mediant 500 MSBR
User's Manual 23. Coders and Profiles
Parameter Description
the coder G.711 A-law/Mu-law with adaptations (see the Note
below).
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 on page 166.

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
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 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.
Note: The corresponding global parameter is
CNGDetectorMode.
Vxx Modem Transport Type
vxx-transport-type
Defines the modem transport type.

[-1] = (Not Configured) The settings of the global parameters