AudioCodes Mediant 3000 User Manual page 718

Parameter
Generation
[ComfortNoiseNegotiati
on]
[SDPEcanFormat]
Web/EMS: First Call
Ringback Tone ID
[FirstCallRBTId]
User's Manual

[1] Enable (default)
The use of CN is indicated by including a payload type for CN on the
media description line of the SDP. The device can use CN with a codec
whose RTP time stamp clock rate is 8,000 Hz (G.711/G.726). The static
payload type 13 is used. The use of CN is negotiated between sides.
Therefore, if the remote side doesn't support CN, it is not used.
Regardless of the device's settings, it always attempts to adapt to the
remote SIP UA's request for CNG, as described below.
To determine CNG support, the device uses the
ComfortNoiseNegotiation parameter and the codec's SCE (silence
suppression setting) using the CodersGroup parameter.
If the ComfortNoiseNegotiation parameter is enabled, then the following
occurs:

If the device is the initiator, it sends a "CN" in the SDP only if the
SCE of the codec is enabled. If the remote UA responds with a "CN"
in the SDP, then CNG occurs; otherwise, CNG does not occur.

If the device is the receiver and the remote SIP UA does not send a
"CN" in the SDP, then no CNG occurs. If the remote side sends a
"CN", the device attempts to be compatible with the remote side and
even if the codec's SCE is disabled, CNG occurs.
If the ComfortNoiseNegotiation parameter is disabled, then the device
does not send "CN" in the SDP. However, if the codec's SCE is
enabled, then CNG occurs.
Defines the echo canceller format in the outgoing SDP. The 'ecan'
attribute is used in the SDP to indicate the use of echo cancellation.

[0] = (Default) The 'ecan' attribute appears on the 'a=gpmd' line.

[1] = The 'ecan' attribute appears as a separate attribute.

[2] = The 'ecan' attribute is not included in the SDP.

[3] = The 'ecan' attribute and the 'vbd' parameter are not included in
the SDP.
Note: This parameter is applicable only when the IsFaxUsed parameter
is set to 2, and for re-INVITE messages generated by the device as
result of modem or fax tone detection.
Defines the index of the first ringback tone in the CPT file. This option
enables an Application server to request the device to play a distinctive
ringback tone to the calling party according to the destination of the call.
The tone is played according to the Alert-Info header received in the
180 Ringing SIP response (the value of the Alert-Info header is added
to the value of this parameter).
The valid range is -1 to 1,000. The default is -1 (i.e., play standard
ringback tone).
Notes:

It is assumed that all ringback tones are defined in sequence in the
CPT file.

In case of an MLPP call, the device uses the value of this parameter
plus 1 as the index of the ringback tone in the CPT file (e.g., if this
value is set to 1, then the index is 2, i.e., 1 + 1).
718
Description
Document #: LTRT-89729
Mediant 3000