AudioCodes Mediant 3000 User Manual page 415

User's Manual
Parameter
Extension Coders
[IpProfile_SBCExtensionCoders
GroupID]
Allowed Coders
[IpProfile_SBCAllowedCodersG
roupID]
Allowed Coders Mode
[IpProfile_SBCAllowedCodersM
ode]
Version 7.0
have different media capabilities), by implementing DSP
transcoding. This enables the device to receive capabilities that
are not negotiated between the SIP entities. For example, it can
enforce gain control to use voice transcoding even though both
legs have negotiated without the device's intervention (such as
extension coders).
For more information on extension coders and transcoding, see
Coder Transcoding on page 562,
Notes:

To implement transcoding, you must configure the number of
required DSP channels for transcoding (using the
MediaChannels parameter). Each transcoding session uses two
DSP resources.

The corresponding global parameter is TranscodingMode.
Assigns a Coder Group used for extension coders, added to the
SDP offer in the outgoing leg for the SIP entity associated with the
IP Profile. This is used when transcoding is required between two
IP entities (i.e., the SDP answer from one doesn't include any
coder included in the offer previously sent by the other).
For more information on extension coders and transcoding, see
Coder Transcoding on page 562,
To configure Coders Groups, see Configuring Coder Groups on
page 385.
Assigns an Allowed Audio Coders Group. This defines audio
(voice) coders that can be used for the SIP entity associated with
the IP Profile.
To configure Allowed Audio Coder Groups, see Configuring
Allowed Audio Coder Groups on page 591.
For a description of the Allowed Coders feature, see ''Restricting
Coders'' on page 561.
Defines the mode of the Allowed Coders feature for the SIP entity
associated with the IP Profile.

[0] Restriction = In the incoming SDP offer, the device uses only
Allowed coders; the rest are removed from the SDP offer (i.e.,
only coders common between those in the received SDP offer
and the Allowed coders are used). If an Extension Coders
Group is also assigned (using the 'Extension Coders'
parameter, above), these coders are added to the SDP offer if
they also appear in Allowed coders.

[1] Preference = The device re-arranges the priority (order) of
the coders in the incoming SDP offer according to their order of
appearance in the Allowed Coders Group or Allowed Video
Coders. The coders in the original SDP offer are listed after the
Allowed coders.

[2] Restriction and Preference = Performs both Restriction and
Preference.
Notes:

The parameter is applicable only if Allowed coders are assigned
to the IP Profile (using the 'Allowed Coders' or 'Allowed Video
Coders Group ID' parameters).
415
20. Coders and Profiles
Description
Mediant 3000