AudioCodes Mediant 2000 User Manual page 507

SIP User's Manual
Parameter
EMS: NSE Payload Type
[NSEPayloadType]
EMS: T38 Use RTP Port
[T38UseRTPPort]
Web/EMS: T.38 Max
Datagram Size
[T38MaxDatagramSize]
Web/EMS: T38 Fax Max
Buffer
[T38FaxMaxBufferSize]
Web/EMS: Enable Fax Re-
Routing
[EnableFaxReRouting]
Version 6.4
with NSE Bypass. The bypass packet interval is selected according to
the FaxModemBypassBasicRtpPacketInterval parameter.
Notes:

This feature can be used only if the VxxModemTransportType
parameter is set to 2 (Bypass).

If NSE mode is enabled, the SDP contains the following line:
'a=rtpmap:100 X-NSE/8000'.

To use this feature:

The Cisco gateway must include the following definition:
'modem passthrough nse payload-type 100 codec g711alaw'.

Set the Modem transport type to Bypass mode
(VxxModemTransportType is set to 2) for all modems.

Configure the gateway parameter NSEPayloadType = 100.

This parameter can also be configured per IP Profile, using the
IPProfile parameter (see ''Configuring IP Profiles'' on page 204).
Defines the NSE payload type for Cisco Bypass compatible mode.
The valid range is 96-127. The default value is 105.
Note: Cisco gateways usually use NSE payload type of 100.
Defines the port (with relation to RTP port) for sending and receiving
T.38 packets.

[0] = Use the RTP port +2 to send/receive T.38 packets (default).

[1] = Use the same port as the RTP port to send/receive T.38
packets.
Notes:

For this parameter to take effect, you must reset the device.

When the device is configured to use V.152 to negotiate audio and
T.38 coders, the UDP port published in SDP for RTP and for T38
must be different. Therefore, set the T38UseRTPPort parameter to
0.
Defines the maximum size of a T.38 datagram that the device can
receive. This value is included in the outgoing SDP when T.38 is used.
The valid range is 120 to 600. The default value is 238.
Defines the maximum size (in bytes) of the device's T.38 buffer. This
value is included in the outgoing SDP when T.38 is used for fax relay
over IP.
The valid range is 500 to 3000. The default value is 1024.
Enables re-routing of Tel-to-IP calls that are identified as fax calls.

[0] Disable = Disabled (default).

[1] Enable = Enabled.
If a CNG tone is detected on the Tel side of a Tel-to-IP call, the prefix
"FAX" is appended to the destination number before routing and
manipulations. A value of "FAX" entered as the destination number in
the Outbound IP Routing Table' is then used to route the call and the
destination number manipulation mechanism is used to remove the
"FAX" prefix, if required.
If the initial INVITE used to establish the voice call (not fax) was
already sent, a CANCEL (if not connected yet) or a BYE (if already
connected) is sent to tear down the voice call.
Notes:

To enable this feature, set the parameter CNGDetectorMode to 2
507
A. Configuration Parameters Reference
Description
November 2011