Administrator's Guide

Features and technical reference
555-233-5061680 Issue 5 October 2002
D-Channel Backup activation
■ D-Channel Failure
If the signaling link fails on the active D-channel (D1) or the hardware
carrying D1 fails, the system sends a message over the standby D-channel
(D2). D2 then becomes the active D-channel and carries all subsequent
signaling messages. When the signaling link or hardware on D1 recovers
from the failure, D1 becomes the standby D-channel.
■ System Technician Commands
If a system technician commands that a D-channel switchover take place,
the first action taken by the system is to tear down the signaling link on D1.
After this is completed, a message is sent on D2 to request that D2 become
the active D-channel. D2 then becomes the active D-channel and the
switchover is complete.
Screens used to administer FAS and NFAS
The following list shows the required screens and the fields you must use on each
screen:
■ Signaling Group (Also see the DEFINTY services documentation for
information about this screen.)
— all
■ ISDN trunk group
— Port
— Sig Grp
■ DS1 Circuit Pack
— Signaling Mode
Guidelines for administering FAS and NFAS
Coordinate the following when implementing FAS and NFAS:
■ Decide which T1/E1 facilities will use FAS.
■ Decide which of the remaining T1/E1 facilities carries D-channel signaling
information on the 16th (E1) or 24th (T1) channel. For those channels that
have a D-Channel Backup, D-channel pairs must be allocated.