Avaya Communication Manager Administrator's Manual page 1538

Feature Reference
Facility and Non-Facility Associated Signaling
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
screen.)
— all
•
Trunk Group(s)
—
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.
•
Define Signaling Groups. A Signaling Group is a group of B-channels for which a given
D-channel (or D-channel pair) carries the signaling information. Each Signaling Group must be
designated as either a FAS or NFAS Signaling Group.
— A FAS Signaling Group must contain all the ISDN B-Channels on the T1/E1 interface
associated with the group's D-channel, and cannot contain B-channels from any other DS1
circuit pack. For 24-channel DS1 boards, some of the DS1 ports may use in-band
(robbed-bit) signaling and be members in a tie trunk group rather than an ISDN trunk
group. These tie trunks cannot be members of a Signaling Group.
— There is no restriction on which T1/E1 ports can belong to an NFAS Signaling Group.
Normally, an NFAS Signaling Group consists of one or two D-channels and several
complete T1/E1 interfaces.
— If a Signaling Group contains only a subset of a T1/E1's B-channels (ports 1–12, for
example), it is considered an NFAS Signaling Group, not a FAS Signaling Group. The
remaining B-channels on the T1/E1 are then assigned as members of another NFAS
Signaling Group.
1538
(Also see the DEFINTY services documentation for information about this
Administrator's Guide for Avaya Communication Manager
November 2003