AudioCodes Mediant 500L MSBR

User's Manual 848 Document #: LTRT-10466
Mediant 500L MSBR
Parameter Description
[HandleG711asVBD]
Enables the handling of G.711 as a G.711 Voice Band Data (VBD)
coder.
 [0] = (Default) Disable. The device negotiates G.711 as a regular
audio coder and sends an answer only with G.729 coder. For
example, if the device is configured with G.729 and G.711 VBD
coders and it receives an INVITE with an SDP offer containing
G.729 and “regular” G.711 coders, it sends an SDP answer
containing only the G.729 coder.
 [1] = Enable. The device assumes that the G.711 coder received
in the INVITE SDP offer is a VBD coder. For example, if the
device is configured with G.729 and G.711 VBD coders and it
receives an INVITE with an SDP offer containing G.729 and
“regular” G.711 coders, it sends an SDP answer containing G.729
and G.711 VBD coders, allowing a subsequent bypass
(passthrough) session if fax/modem signals are detected during
the call.
Note: This parameter is applicable only if G.711 VBD coder(s) with
regular G.711 payload types 0 or 8 are configured for the device
(using the CodersGroup parameter).
CLI: fax-vbd-behvr
[FaxVBDBehavior]
Determines the device's fax transport behavior when G.711 VBD
coder is negotiated at call start.
 [0] = (Default) If the device is configured with a VBD coder (see
the CodersGroup parameter) and is negotiated OK at call start,
then both fax and modem signals are sent over RTP using the
bypass payload type (and no mid-call VBD or T.38 Re-INVITEs
occur).
 [1] = If the IsFaxUsed parameter is set to 1, the channel opens
with the FaxTransportMode parameter set to 1 (relay). This is
required to detect mid-call fax tones and to send T.38 Re-INVITE
messages upon fax detection. If the remote party supports T.38,
the fax is relayed over T.38.
Notes:
 If VBD coder negotiation fails at call start and if the IsFaxUsed
parameter is set to 1 (or 3), then the channel opens with the
FaxTransportMode parameter set to 1 (relay) to allow future
detection of fax tones and sending of T.38 Re-INVITES. In such a
scenario, the FaxVBDBehavior parameter has no effect.
 This feature can be used only if the remote party supports T.38
fax relay; otherwise, the fax fails.
[NoAudioPayloadType] Defines the payload type of the outgoing SDP offer.
The valid value range is 96 to 127 (dynamic payload type). The
default is 0 (i.e. NoAudio is not supported). For example, if set to
120, the following is added to the INVITE SDP:
a=rtpmap:120 NoAudio/8000\r\n
Note: For incoming SDP offers, NoAudio is always supported.