Polycom MGC Administrator, Руководство администратора

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MGC Administrator’s Guide
7-37
Gateway Session Profiles
A Session Profile defines how the call leaves the gateway (which network is
used to handle the call), and how to establish the connection with the
destination endpoint, mainly which line rate to use, and the Transcoding
mode. All these parameters are defined in the Session Profile.
The following section describes the various session parameters that are
defined in the Session Profile.
Network Services
The MGC unit is designed to work with different telephone carriers. In
particular, the MGC unit can be connected to any public or private network
that supplies ISDN lines, leased lines, ATM connections or IP connections.
These include long distance carrier services and local area services. In
addition, the MGC unit may be connected to a serial network using the MPI
serial network interface card.
Line Rate
The transfer rate of multimedia (audio and video) between the two endpoints.
The maximum line rate currently supported for H.323 participants is E1
(1920 Kbps).
Transcoding
Transcoding enables participants using different line rates and video formats
to communicate, thus maintaining the highest video capabilities each
participant can achieve with his/her endpoint. There are three Transcoding
modes:
None , When Required and Always .
None - No Transcoding.
When Required - Automatic Switching to Transcoding when the system
identifies the need.
Always - Transcoding is always used.
Audio Only
When one of the endpoints cannot use video or is a telephone, the session is
defined as
Audio Only .
Restricted
In restricted lines, the line rate of each channel is 56 Kbps instead of 64 Kbps.
This option is primarily for the United States. If one of the endpoints is using
Restricted lines, the gateway session should be set to
Restricted .