[c-nsp] Line Code Violations on DS3

[Jay Hennigan]

Nick Voth wrote:
> 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

Wow, that's a lot of errors.  We've found two things:

1. You may need an attenuator on the receive side at the controller.

2. In one case we had Westell DS-3 smartjacks in the telco mux and 
discovered that the CT3 cards became unhappy when regeneration was 
enabled on the smartjack towards the CPE.  These can be configured with 
a serial cable plugged in to the DB-9 port on the smartjack, simple menu 
interface.

--
Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net
Impulse Internet Service  -  http://www.impulse.net/
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