Esa Operation - Nortel DMS-100 Series Maintenance Manual

OPAC hardware representation in ESA operation
0
Unit 0
0
Unit 0
0
RMM

ESA operation

The OPAC enters ESA mode when the OPAC loses the ability to
communicate with the host site. Two conditions cause ESA mode at the
OPAC:
When the OPAC enters ESA mode, the system takes down all active calls,
which causes a cold enter condition.
The line concentrating module (LCM) detects loss of communication with
the host.
When the LCM determines the ESA mode is necessary, the LCM switches
the C-side links from the host to the ESA processor. The ESA processor
uses the tone and clock card to detect the link switch.
When the ESA processor detects the link switch, the system initiates ESA
enter. The type of failure determines the time span between loss of
communication and ESA mode.
1 2
Unit 1
2 1
Unit 1
2 1
communication links that the system cannot use
loop-around message audit failure
DMS-100 Family OPAC Maintenance Manual XPM12 and up
ESA maintenance overview 3-3
3
(up to 32 DS30 links)
LTC
(Links between the
3 OPAC and the LTC are
inoperable.)
OPAC
3
ESA processor acts as the
host PM. Links 2 and 3
act as P-side single
channel message links to
the OPAC.
ESA