North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: Bell Atlantic DACS failure 280 T3s

  • From: Steven Schnell
  • Date: Wed May 17 08:52:02 2000

A DCS has the capability to loop any DS-0, DS-1 or DS-3 signal onto itself
or any other signal in the digital crossconnect system's electronic matrix. 
Whether or not the DCS has a test head (e.g., Hekemian or other) outboard or
integrated in the DCS is a choice of the carrier.  At the command of a DCS
admin person a digital signal can be crossconnected to the test head's test
port on the DCS, where it can be remotely tested for continuity, signal
impairments or other operating parameters.  DDS and/or DS-n signals can be
generated by the test head and the circuit's response compared against a
"signal mask" stored in the test head.  Whether or not the circuit meets the
carrier's standards for Bit Error Rate (BER) and other operating parameters
can be quickly ascertained.

I can't believe that Bell Atlantic does not have this capability within
their network.

NetEffect Corporation

------Original Message------
From: Travis Pugh <[email protected]>
To: Sean Donelan <[email protected]>
Sent: May 16, 2000 8:54:22 PM GMT
Subject: Re: Bell Atlantic DACS failure 280 T3s

I'm curious about BA DACS.  I don't know if this is standard, but they
are the only telco who has also told me "we put a loop up on the DACS,
but sometimes it doesn't work ... so don't assume that it is a valid
test."  And I have witnessed that same happening.  If you can't create a
simple maintenance loop on BA's DACS, their choice of vendors does seem


On 16 May 2000, Sean Donelan wrote:

> Bell Atlantic lost another DACS yesterday taking out 280 T3s for 3-1/2
> in the northeastern corridor and New York City.
> I'm not a transmission person, but what is the problem with DACS?  Why
> do these "highly reliable" systems fail in such catastrophic ways?