AudioCodes E-SBC User Manual page 429

CHAPTER 19 Coders and Profiles
Allowed Audio Coders Groups restrict coders for SIP entities. Only coders listed in the Allowed
Audio Coders Group (i.e., allowed coders) that is associated with the SIP entity can be used. If the
coders in the SDP offer ('a=rtpmap' field) of the incoming SIP message are not listed in the Allowed
Audio Coders Group, the device rejects the calls , unless transcoding is configured, whereby
"extension" coders are added to the SDP, as described in
contains some coders that are listed in the Allowed Audio Coders Group, the device manipulates
the SDP offer by removing the coders that are not listed in the Allowed Audio Coders Group, before
routing the SIP message to its destination. Thus, only coders that are common between the coders
in the SDP offer and the coders in the Allowed Audio Coders Group are used. For more information
on coder restriction, see
For example, assume the following:
■ The SDP offer in the incoming SIP message contains the G.729, G.711, and G.723 coders.
■ The allowed coders configured for the SIP entity include G.711 and G.729.
The device removes the G.723 coder from the SDP offer, re-orders the coder list so that G.711 is
listed first, and sends the SIP message containing only the G.711 and G.729 coders in the SDP.
To apply an Allowed Audio Coders Group for restricting coders to a SIP entity:
1. Configure an Allowed Audio Coders Group in the Allowed Audio Coders Groups table (see
description below).
2. In the IP Profile associated with the SIP entity (see
● Assign the Allowed Audio Coders Group (using the IpProfile_SBCAl-
lowedAudioCodersGroupName parameter).
● Enable the use of Allowed Audio Coders Groups (by configuring the IpProfile_
SBCAllowedCodersMode parameter to Restriction or Restriction and Preference).
The device also re-orders (prioritizes) the coder list in the SDP according to the order of appearance
of the coders listed in the Allowed Audio Coders Group. The first listed coder has the highest
priority and the last coder has the lowest priority. For more information, see
SDP Offer.
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The following procedure describes how to configure Allowed Audio Coders Groups through the Web
interface. You can also configure it through ini file [AllowedAudioCodersGroups] and
AllowedAudioCoders) or CLI ( configure voip > coders- and- profiles allowed-
audio- coders- groups ; configure
audio-coders < group index/coder index>).
➢
To configure an Allowed Audio Coders Group:
1. Open the Allowed Audio Coders Groups table (Setup menu > Signaling & Media tab >
Coders & Profiles folder > Allowed Audio Coders Groups).
2. Click New; the following dialog box appears:
Restricting Audio
The Allowed Audio Coders Groups table is applicable only to the SBC application.
The Allowed Audio Coders Group for coder restriction takes precedence over the
Coder Group for extension coders. In other words, if an extension coder is not listed
as an allowed coder, the device does not add the extension coder to the SDP offer.
To configure "extension" coders for adding to the SDP offer for audio transcoding,
use the Coder Groups table (see
Mediant 1000 Gateway & E-SBC | User's Manual
Coder
Coders.
Configuring IP
Configuring Coder Groups
voip > coders- and- profiles
- 391 -
Transcoding. If the SDP offer
Profiles):
Prioritizing Coder List in
allowed-