Specifications

Managing IP-PBX Integration Configuring Media Settings
10
ShoreTel Mobility Router Administration Guide 146
 Select Force RTP Bridging through the Mobility Router to bridge RTP media streams through
the ShoreTel Mobility Router. This option is disabled by default.
 Check Mobility Router Transcoding if transcoding between codecs is necessary in the network.
This option is enabled by default for ShoreTel IP-PBXs. Used in combination with Force RTP
Bridging (see above for more information on this option), the following Media Operation Modes
occur:
 RTP Bridging Off/Transcoding On (Default for ShoreTel IP-PBXs): Disable Force RTP
Bridging through the Mobility Router and enable Mobility Router Transcoding to place
the ShoreTel Mobility Router in the media path for the first few seconds of the call. During this
initial period, the Mobility Router assesses if it needs to continue to stay in the media path or if
it can “jump out” based on Codec agreement on both sides. If there is no shared common
Codec on both sides, the Mobility Router re-enters the media path and provides the necessary
transcoding.
 RTP Bridging On/Transcoding On: Enable both Force RTP Bridging through the Mobility
Router and Mobility Router Transcoding to place the ShoreTel Mobility Router in the media
path at all times and perform media transcoding if necessary. In this mode, the Mobility Router
replaces the incoming Session Description Protocol (SDP) with the Mobility Router’s SDP. The
list of Mobility Router-supported Codecs is forwarded to other side, and is reordered according
to incoming SDP Codec list. Codecs that are not present in the incoming SDP but enabled on
the Mobility Router (Refer to step n) are inserted at end of the list. This mode allows the
Mobility Router to be interoperate with the most PBXs, but it could significantly increase the
Mobility Router’s resource (CPU, networking and memory) requirement.
 RTP Bridging On/Transcoding Off: Enable Force RTP Bridging through the Mobility Router
and disable Mobility Router Transcoding to place with ShoreTel Mobility Router in the media
path without transcoding. In this mode, the Mobility Router replaces the incoming Session
Description Protocol (SDP) with the Mobility Router’s SDP. The list of Codecs that is forwarded
to other side is limited and in the same order as in incoming SDP. Additionally, Codecs which
are not supported by the Mobility Router are excluded from the list. RTP packets flow through
Mobility Router, but no transcoding is performed.
Note
Bridging media through the ShoreTel Mobility Router increases the CPU and network load on the
Mobility Router and reduces scalability.
Note
This option may be used in combination with Mobility Router Transcoding. See below in Mobility
Router Transcoding for more information on these Media Operation Modes, and how the Mobility
Router’s performance may be affected by the various combinations of these Modes.
WARNING!
For ShoreTel IP-PBX releases 11.x and older, confirm that Force RTP Bridging is disabled (not
checked); the default may enabled (checked) in these releases.