[c-nsp] Line Code Violations on DS3

[Nick Voth]

Hello folks,

I need another set of eyes on this. We have a new channelized DS3 plugged in
to a Cisco 7206-VXR with a PA-MC-T3 card. We can't seem to get rid of the
Line Code Violations and P-bit Coding Violations. See what we've done below
this output... 

Here the output that shows the errors:

show controller t3
T3 4/0 is up.  Hardware is CT3 single wide port adapter
  CT3 H/W Version : 1.0.1, CT3 ROM Version : 1.1, CT3 F/W Version : 2.4.3
  FREEDM version: 1, reset 0 resurrect 0
  Applique type is Channelized T3
  Description: DS3-1 from XO
  No alarms detected.
  FEAC code received: No code is being received
  Framing is M23, Line Code is B3ZS, Clock Source is Internal
  Rx-error throttling on T1's ENABLED
  Rx throttle total 0, equipment customer loopback
  Data in current interval (611 seconds elapsed):
     2758 Line Code Violations, 1370 P-bit Coding Violation
     0 C-bit Coding Violation, 543 P-bit Err Secs
     0 P-bit Severely Err Secs, 0 Severely Err Framing Secs
     0 Unavailable Secs, 565 Line Errored Secs
     0 C-bit Errored Secs, 0 C-bit Severely Errored Secs
  Total Data (last 3 15 minute intervals):
     13168 Line Code Violations, 6464 P-bit Coding Violation,
     0 C-bit Coding Violation, 2441 P-bit Err Secs,
     0 P-bit Severely Err Secs, 0 Severely Err Framing Secs,
     0 Unavailable Secs, 2507 Line Errored Secs,
     0 C-bit Errored Secs, 0 C-bit Severely Errored Secs



The configuration for the DS3 is here:

controller T3 4/0
 framing m23
 cablelength 53
 description DS3-1 from XO

Pretty simple and I¹ve verified the framing from the telco. They also had me
set the clock source to internal. I¹ve tried ³line² and ³internal² for the
clock source and get errors regardless.

I¹ve run this through the Cisco Output Interpreter and it basically says
check your cables and try loopback testing.

When I loop the DS3 card directly with a piece of coax, I still get the
errors. We¹ve done the reverse, and looped the cable coming to us from the
telco and it has tested clean end-to-end.

It all points to the card, so we replaced it and we get the same thing. I¹ve
even tried different slots in the chassis and no go. Exact same errors
across 2 DS3 cards and on every chassis in the 7206.

We¹re running 12.2(29b) for the IOS as it¹s the latest GD release that Cisco
recommends for this configuration.

Thanks for any ideas....

-Nick Voth