AudioCodes Mediant 2600 - Page 304

User's Manual 304 Document #: LTRT-42060
Mediant 2600 E-SBC
Parameter Description
Web: Allowed Coders Mode
CLI: sbc-allowed-coders-mode
[IpProfile_SBCAllowedCodersM
ode]
Defines the mode of the Allowed Coders feature for this SIP entity.
 [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 Group ID'
parameter, above), these coders are added to the SDP offer.
 [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 tables. The coders received in the SDP offer are listed
after the Allowed coders.
 [2] Restriction and Preference = Performs both Restriction and
Preference.
Notes:

This parameter is applicable only if Allowed coders are assigned
to the IP Profile (using the 'Allowed Coders Group ID' or
'Allowed Video Coders Group ID' parameters).
 For more information on the Allowed Coders feature, see
Restricting Coders on page 331.
Web: SBC Media Security
Behavior
CLI: sbc-media-security-
behaviour
[IpProfile_SBCMediaSecurityBe
haviour]
Defines the handling of RTP and SRTP for this SIP entity.
 [0] As is = (Default) No special handling for RTP\SRTP is done.
 [1] SRTP = SBC legs negotiate only SRTP media lines, and
RTP media lines are removed from the incoming SDP
offer\answer.
 [2] RTP = SBC legs negotiate only RTP media lines, and SRTP
media lines are removed from the incoming offer\answer.
 [3] Both = Each offer\answer is extended (if not already) to two
media lines - one RTP and the other SRTP.
If two SBC legs (after offer\answer negotiation) use different
security types (i.e., one RTP and the other SRTP), the device
performs RTP-SRTP transcoding. To transcode between RTP and
SRTP, the following prerequisites must be met:
 At least one supported SDP "crypto" attribute and parameters.
 EnableMediaSecurity must be set to 1.
If one of the above transcoding prerequisites is not met, then:
 any value other than “As is” is discarded.
 if the incoming offer is SRTP, force transcoding, coder
transcoding, and DTMF extensions are not applied.