Nortel Networks 1000 - Manual (Page 167)

Functional description 167
The RED ALARM LED indicates that the Lineside T1 card has detected
an alarm condition from the T1 link. Alarm conditions can include such
conditions as not receiving a signal or the signal has exceeded bit error
thresholds or frame slip thresholds. See
“Functional description” (page
385) for information on T1 link maintenance.
If one of these alarm conditions is detected, this red LED light. Yellow
alarm indication is sent to the far-end as long as the near-end remains in a
red alarm condition. Depending on how the Man-Machine Interface (MMI)
is configured, this LED remains lit until the following actions occur:
•
If the "Self-Clearing" function has been enabled in the MMI, the LED
clears the alarm when the alarm condition is no longer detected. This
is the factory default.
•
If the "Self-Clearing" function has not been enabled or it has been
subsequently disabled in the MMI, the LED stays lit until the command
"Clear Alarm" has been typed in the MMI, even though the carrier
automatically returned to service when the alarm condition was no
longer detected.
The YELLOW ALARM LED indicates that the Lineside T1 card has
detected a yellow alarm signal from the terminal equipment side of the T1
link. See the
“Functional description” (page 385) for information on T1 link
maintenance. If the terminal equipment detects a red alarm condition, such
as not receiving a signal or the signal has exceeded bit error thresholds or
frame slip thresholds, it can send a yellow alarm signal to the Lineside T1
card, depending on whether or not the terminal equipment supports this
feature. If a yellow alarm signal is detected, the LED lights.
The MAINT LED indicates if the Lineside T1 card is fully operational
because of certain maintenance commands being issued through the
MMI. See
“Functional description” (page 385) for information on T1 link
maintenance. If the card detects that tests are being run or that alarms
are disabled through the MMI, the LED lights and remains lit until these
conditions are no longer detected, then it turns off.
Functional description
Figure 30 "Lineside T1 card - block diagram" (page 169) shows a block
diagram of the major functions contained on the Lineside T1 card. Each of
these functions is described on the following pages.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.