Administrator's Guide

Managing data calls
555-233-506510 Issue 5 October 2002
If an AC drops because it was disabled/removed or is no longer due to be active,
no action is taken. If an AC drops because of changed AC attributes, an immediate
attempt is made to establish the connection with the changed attributes if it is still
due to be active. Existing entries in the error/alarm log are resolved if they no
longer apply. If handshake failure resulted in the dropping of the connection, in
the case of an AC involving at least one data endpoint, no action is taken for that
AC until the change administered-connection
command is executed.
Administered Connections failure: Auto
Restoration and Fast Retry
When an active AC drops prematurely, you must invoke either auto restoration or
fast retry to determine whether auto restoration is attempted for an active AC.
If you option AC for auto restoration and the connection was routed over SDDN
trunks, auto restoration is attempted. During restoration, connections are
maintained between the switch and both endpoints. In addition to allowing the
active session to be maintained, AC also provides a high level of security by
prohibiting other connections from intervening in active sessions. Auto
restoration generally completes before the 60-second endpoint holdover interval.
If auto restoration is successful, the call might be maintained (no guarantee). The
restoration is transparent to the user with the exception of a temporary disruption
of service while restoration is in progress. A successful restoration is reflected by
the restored state on the status AC screen. Although the restoration was
successful, the data session may not have been preserved.
If auto restoration is not active or if the AC is not routed over SDDN trunks, the
switch immediately attempts to reestablish the connection (fast retry). The switch
also attempts a retry if the originating endpoint initiated the drop. With fast retry,
connections are not maintained on both ends. Fast Retry is not attempted for an
AC that was last established via fast retry, unless the AC is active for at least two
minutes.
If auto restoration or fast retry fails to restore or reestablish the connection, the
call drops and the AC goes into retry mode. Retry attempts continue, at the
administered retry interval, as long as the AC is due to be active.