[c-nsp] E1 packet loss

[Rens]

Hi all,

I have 2 routers that are connected via a 3rd party E1 circuit.
When I ping between my routers I have packet loss.
I have done a BER test on the E1 circuit which comes out clean.
Already replaced both E1 cards and my cabling, but still having packet loss
(between 30 & 10% depending on size)

I have followed the E1 error events troubleshooting for the line code
violations & path code violations but line code is configured correctly...

What are the next steps that I can take?
Below is my config + the show controller output

Side A:

controller E1 0/1
 framing NO-CRC4 
 clock source internal
 channel-group 0 timeslots 1-31

interface Serial0/1:0
ip address x.x.x.1 255.255.255.252

show controllers E1 0/1
E1 0/1 is up.
  Applique type is Channelized E1 - balanced
  No alarms detected.
  alarm-trigger is not set
  Version info Firmware: 20040108, FPGA: 11
  Framing is NO-CRC4, Line Code is HDB3, Clock Source is Internal.
  CRC Threshold is 320. Reported from firmware  is 0.
  Data in current interval (24 seconds elapsed):
     0 Line Code Violations, 0 Path Code Violations
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

Side B:

controller E1 0
 framing NO-CRC4 
 channel-group 0 timeslots 1-31

interface Serial0:0
ip address x.x.x.2 255.255.255.252

sh controllers E1 0
E1 0 is up.
  Applique type is Channelized E1 - balanced
  No alarms detected.
  alarm-trigger is not set
  Version info Firmware: 20040928, FPGA: 11, spm_count = 0
  Framing is NO-CRC4, Line Code is HDB3, Clock Source is Line.
  CRC Threshold is 320. Reported from firmware  is 320.
  Data in current interval (20 seconds elapsed):
     2689 Line Code Violations, 53 Path Code Violations
     0 Slip Secs, 0 Fr Loss Secs, 20 Line Err Secs, 0 Degraded Mins
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 20 Unavail Secs

Regards,

Rens