Version 6.2
495
February 2011
SIP User's Manual
8. IP Telephony Capabilities
Media port number
RTCP media attribute IP address and port (if the parameter EnableRTCPAttribute is
set to 1)
Each SBC leg allocates and uses the device's local ports (e.g., for RTP\RTCP\fax). The
local ports are allocated from a Media Realm associated with each leg. The legs are
associated with a Media Realm as follows: If the leg's IP Group is configured with a Media
Realm, then this is the associated Media Realm; otherwise, the leg's SRD Media Realm is
the associated one. The figure below illustrates an example of SDP handling for a call
between IP Phone 10.2.2.6 (LAN) and a remote IP Phone 212.179.1.13 ().
Figure
8-54: SDP Offer/Answer Example
8.4.5.2 Media Anchoring with Transcoding
The device performs transcoding when there are no common coders between the two user
agents (i.e., the SDP answer from one user agent doesn't include any coder included in the
offer previously sent by the other user agent). For transcoding, the device can be
configured to add media capabilities to user agents pertaining to a specific IP Group, and
then perform transcoding in cases where the selected coder in the answer SDP is not one
that appears in the original offer. The capabilities that can be added are one or more of the
device's supported coders and are configured by using the parameter
SBCExtensionCodersGroupID (points to a coders list) in the IP Profile table (which is
assigned to the IP Group). Therefore, to allow user agents of different IP Groups to
communicate with each other (regardless of their capabilities), an extended coders table
with at least one coder that is supported by each IP Groups' user agents needs to be
assigned to each IP Group. Therefore, each offer destined to specific IP Groups include
this coder.
Summary of Contents for Mediant 800 MSBG
Page 2: ......
Page 366: ...SIP User s Manual 366 Document LTRT 12804 Mediant 800 MSBG Reader s Notes ...
Page 372: ...SIP User s Manual 372 Document LTRT 12804 Mediant 800 MSBG Reader s Notes ...
Page 390: ...SIP User s Manual 390 Document LTRT 12804 Mediant 800 MSBG Reader s Notes ...
Page 404: ...SIP User s Manual 404 Document LTRT 12804 Mediant 800 MSBG Reader s Notes ...
Page 616: ...SIP User s Manual 616 Document LTRT 12804 Mediant 800 MSBG Reader s Notes ...
Page 636: ...SIP User s Manual 636 Document LTRT 12804 Mediant 800 MSBG Reader s Notes ...
Page 652: ...SIP User s Manual 652 Document LTRT 12804 Mediant 800 MSBG Reader s Notes ...
Page 886: ...SIP User s Manual 886 Document LTRT 12804 Mediant 800 MSBG Reader s Notes ...