Configuring The Mgc List - Avaya G250 Administration Manual

Basic device configuration
Enhanced Local Survivability (ELS). ELS is available for the G250 and G350 using a
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local S8300 or S8500 functioning in LSP mode. If the ECC stops serving the G250/G350,
the S8300 takes over the service.
Auto fallback to primary MGC. This feature provides a means by which a G250/G350
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being serviced by its LSP can return to its primary MGC automatically when the
connection is restored between the G250/G350 and the MGC. By migrating the
G250/G350 to the MGC automatically, a fragmented network can be made whole faster,
without the need for human intervention. Auto fallback is configured via the Avaya
Communication Manager. For details, see the Administrator Guide for Avaya
Communication Manager, 03-300509.
Note:
Auto fallback does not include survivability. Therefore, there is a short period
Note:
during registration with the MGC during which calls are dropped and service is
not available. This problem can be minimized using the connection preservation
feature described below.
Connection preservation. This feature enables the G250/G350 to preserve the bearer
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paths of stable calls in the event that the G250/G350 migrates to another MGC (including
an LSP), including migration back from an LSP to the primary MGC. A call for which the
talk path between parties in the call has been established is considered stable. A call
consisting of a user listening to announcements or music is not considered stable and is
not preserved. Any change of state in the call prevents the call from being preserved. For
example, putting a call on hold during MGC migration will cause the call to be dropped.
Special features, such as conference and transfer, are not available on preserved calls.
Connection preservation preserves all types of bearer connections except BRI. PRI trunk
connections are also preserved. Connection preservation is configured via the Avaya
Communication Manager. For details, see the Administrator Guide for Avaya
Communication Manager, 03-300509.
Modem dial-backup. This feature can be used to provide redundant WAN connectivity
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between a G250/G350 and its primary MGC using a serial modem. This connection uses a
virtual interface called the Dialer interface. This feature recognizes that even if the
G250/G350 is configured for survivability via SLS or ELS, the best solution is to maintain
the gateway's connection with its primary MGC whenever possible. For details on
configuring a backup Dialer interface, see

Configuring the MGC list

The G250/G350 must be registered with an MGC in order to provide telephone service. You can
set the G250/G350's MGC, and show the current MGC list used to determine the results.
94 Administration for the Avaya G250 and Avaya G350 Media Gateways
Modem dial backup on page 291.