Re: PM3 alarms

Kyle Platts (kwplat1@reliant.uswc.uswest.com)
Thu, 28 Aug 97 09:44:05 -0500

>Last night, our PM3 (PRI) running ComOS 3.7 with the OLD modem =
cards,
recevied it's
first blue alarms. I tried browsing the livingson site and the =
archives for
any info on this
but got zilch. Can anyone help explain what happened or point me =
to some info.

---------------------- line0 - T1 Primary Rate ISDN =
---------------

Status: UP Framing: ESF Encoding: B8ZS PCM: =
u-law
=20
Receive Level: +2dB to -7.5dB

Alarms Violations
----------------------------- =
-----------------------------
Blue 2 Bipolar =
0
Yellow 0 CRC Errors =
0
Receive Carrier Loss 0 Multiframe Sync =
115
Loss of Sync 2

Here is a typical circuit layout.=20

switch ---- dacs ---- transport ----- niu --- pm3

A blue alarm is an all ones keep alive signal. The situation you =
would most likely see a blue alarm, is when a piece of intelligent =
equipment loses carrier, instead of dropping the signal, it sends =
the all ones keep alive. Let's say for instance that the span =
between the switch and the dacs failed. The dacs would then send =
the all ones to you rather than just dropping the signal. If the =
span had failed between the dacs and the niu, you would have seen =
a red alarm, loss of signal, or all zeros. Of course, your mileage =
may vary, since I do not know the deisgn of your circuit.=20

Kyle Platts
CSS-Tech
!NTERPRISE Networking Services=