[c-nsp] Incrementing input errors and ignored counters on POS OC48 interface

[Aaron Daubman]

Greetings,

I'm trying to determine the cause of incrementing 'input error' and
'ignored' counters on my GSR12410's OC48 LC.

Searching around, it seems ignored errors are usually due to exceeding
buffers/no mem drops:
http://www.cisco.com/warp/public/63/ignored_nomem_18003.html

This doesn't appear to be the case, however (after running the show
commands in the link above, and the input stream is only ~95Mbps...)

The network is a lab setup:

[Ixia](OC48)<==>(OC48)[ONS15454](OC48)<==>(OC48)[GSR](GigE)<==>[Ixia](GigE)

Any suggestions on how to troubleshoot further?

Relevant output follows:
---snip---
GSR-1#sh ru | b SONET
controller SONET 0/0
  sts-1 1 - 48 pos
!


GSR-1#sh ru i p0/0:1
Building configuration...

Current configuration : 217 bytes
!
interface POS0/0:1
  no ip address
  no ip directed-broadcast
 load-interval 30
  carrier-delay msec 0
  no keepalive
 ipv6 address FE80::200:FF:FE02:101 link-local
 ipv6 enable
  ipv6 cef
  crc 32
  pos scramble-atm
end


GSR-1#show interfaces POS 0/0:1 controller
POS0/0:1 is up, line protocol is up
  Hardware is Packet over SONET
  MTU 4470 bytes, BW 2488000 Kbit, DLY 100 usec, rely 255/255, load 1/255
  Encapsulation HDLC, crc 32, loopback not set
  Keepalive not set
  Scramble enabled
  Carrier delay is 0 msec
  Last input 1d03h, output 00:00:11, output hang never
  Last clearing of "show interface" counters 00:07:32
  Queueing strategy: fifo
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
        Available Bandwidth 2395851 kilobits/sec
  30 second input rate 0 bits/sec, 0 packets/sec
  30 second output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
              0 parity
     4500773 input errors, 0 CRC, 0 frame, 0 overrun, 4500773 ignored, 0 abort
     8 packets output, 2808 bytes, 0 underruns
     0 output errors, 0 applique, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions

POS0/0:1
PATH
  AIS = 0          RDI    = 0          FEBE = 0          BIP(B3) = 0
  LOP = 0          NEWPTR = 0          PSE  = 0          NSE     = 0

Active Defects: None
Active Alarms:  None
Alarm reporting enabled for: PLOP B3-TCA

  S1S0 = 00, C2 = 16
PATH TRACE BUFFER : STABLE
  Remote hostname :
  Remote interface:
  Remote IP addr  :
  Remote Rx(K1/K2):   /    Tx(K1/K2):   /

BER thresholds:  B3 = 10e-6
---snip---

Thanks,
     ~Aaron