[c-nsp] Line Code Violations on DS3

[Jon Lewis]

On Wed, 30 Jan 2008, Nick Voth wrote:

>> 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 Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
_________ http://www.lewis.org/~jlewis/pgp for PGP public key_________