Exiting Esa Mode - Nortel DMS-100 Series Maintenance Manual

• primary numbers of the multiple appearance directory number (MADN)
groups are treated as standard MDC lines
• multiple centrex customer dialing plans

Exiting ESA mode

After communications restore, the DMS-100 CC recovers the Star Hub from
the ESA mode. When the Star Hub exits ESA mode, the active calls go out of
service. This action is a cold exit.
When C-side communications restore between the Star Hub and the DMS-100
CC, the DMS-100 CC initiates the ESA exit sequence. Before the ESA exit
sequence begins, the DMS-100 CC communicates with the ESA software over
the nailed-up connection. This communication determines if the Star Hub is
in ESA mode and if recovery of the Star Hub can occur immediately. The two
methods the Star Hub can recover are a system exit or a manual exit.
ESA system exit
A system exit is an automatic exit from ESA mode the DMS-100 CC starts.
This exit does not require operator interference. The DMS-100 CC starts a
system exit if the following conditions are present:
• A minimum of one unit of the Star Hub is SysB or C-side busy (CBsy)
• The RLCM_XPMESAEXIT office parameter time-out value is not zero.
The following list of steps is the system exit sequence:
1. The C-side communications are restored between the DMS-100 CC and
the Star Hub.
2. The DMS-100 CC determines the Star Hub is in ESA mode.
3. The DMS-100 CC enters the ESA time-out period. During this period the
CC communicates with the Star Hub every 10 s to determine if the C-side
links are still OK. If communication fails again during the time-out
period, the CC will not continue with the ESA exit.
4. When the DMS-100 CC time out period expires, the DMS-100 CC sends
an ESA-exit request to the Star Hub. The CC does not know which of the
units is ESA active, so it sends the exit request to a unit that has a good
C-side link. If the message arrives at the ESA inactive unit, this unit
transfers the message to the mate unit.
5. The Star Hub and the ESA software in the RCP perform exit operations.
6. The ESA software tells the RCP to return the Star Hub to normal
operations.
7. The ESA software in the RCP sends operational measurements (OM), peg
counts, and the reason for the entry of ESA mode back to the DMS-100
DMS-100 Family NA100 Star Remote System XPM15 and up
ESA maintenance overview 5-13