Friday, September 4, 2009

ISDN Alarms indications in zaptel/Dahdi

The TE200 series user manual contains only a description of LEDs states.

These alarmsstates are visible in zttool/dahditool or in astersick CLI (zap show status)

You have three different general alarm states:

Red alarm
Your T1/E1 port will go into red alarm when it maintain
synchronization with the remote switch. A red alarm
typically indicates either aphysical wiring problem,
loss of connectivity, or a framing and/or line-coding
mismatch with the remote switch. When your T1/E1 port
loses sync, it will transmit a yellow alarm to the remote
switch to indicatethat it's having a problem receiving
signal from the remore switch.(The easy way to remember
this is that the R in red stands for "right here" and "receive".
.. indicating that we're having a problem right here
receiving the signal from the remote switch.)

Yellow alarm or RAI (Remote Alarm Indication)
Your T1/E1 port will go into yellow alarm when it receives a
signal from the remote switch that the port on that remote
switch is in red alarm.This essentially means that the remote
switch is not able to maintain sync with you, or is not receiving
your transmission. (The easy way to remember this is that t
he Y in yellow stands for "yonder"... indicating that the
remote switch (over yonder) isn't able to see what you're

Blue alarm or AIS (Alarm Indication Signal)
Your T1/E1 port will go into blue alarm when it receives all
unframed 1s on all timeslots from the remote switch. This is
a special signal to indicate that the remote switch is
having problems with it's upstream connection.

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