[c-nsp] Line Code Violations on DS3

[Gregory Boehnlein]

> >> Try putting a 12 db attenuator on the transmit portion, then re-try
> your
> >> loopback. We've found that the PA-MC-T3 cards tend to overdrive the
> DS3 a
> >> bit, and the only way that we've been able to get rid of the errors
> is
> >> attenuating the transmit load.
> >
> > Interesting, you're saying to put an attenuator on the transmit
> portion of
> > the card. Some of the Cisco documentation is saying to put it on the
> receive
> > portion. Is there any way using the "show controller" output to tell
> which
> > one has the "hot" signal?
> 
> He meant on the PA's receive (the telco's transmit).  PA-MC-T3s are
> somewhat notorious for being sensitive to overly hot signals...where
> cisco's definition of 'overly hot' is 'normal' to several other
> vendors.
> 
> In a pinch, if you can't find a suitable attenuator, you can use a
> really long service loop and/or multiple DS3 cables connected together
> using barrel connectors.  We have at least one installation where after
> switching from a CAC Widebank28 to an Adtran mux, we ended up needing a
> coiled up 50' "service loop" sitting on top of the mux to keep the
> PA-MC-T3 happy.

Jon, yes.. thank you .. that was exactly what I was getting at.. 

We, too, have several DS3's w/ 75 feet of coiled up cable sitting in the
bottom of a cabinet to get the Adtran MX-2800s and the PA-MC-CT3's to play
nice together. I know that to most people that sounds counter intuitive, but
keep in mind the signals were meant to be driven over much longer distances
than the typical 6 foot Patch Panel to CPE that exists in lots of data
center installations.