[c-nsp] E3 between Cisco 7200 and Juniper

[Shiraz]

Hi,

I'm trying to bring up and E3 circuit between Cisco 7204VXR (my end) and a
Juniper router (up stream provider) for last almost 5 days. The only problem
I'm facing right now is the random increase in the Input Errors and CRC on
Cisco E3 interface. 

Extended BERT tests from both sides show that media is perfectly fine
between 2 ends. Extended ping tests from both ends on the looped interfaces
show the same result i.e. no packet loss. However, when media is connected
to the interfaces on the both ends, CRC and Input errros are observed on the
Cisco end.


-------------------------------------------
Following is the configuration on the Cisco:

sh run int s1/1
---------------
interface Serial1/1
 mtu 4474
 ip address a.b.c.d 255.255.255.252
 encapsulation ppp
 load-interval 30
 framing g751
 dsu bandwidth 34010
 dsu mode 1
 serial restart_delay 0
end

sh controllers s1/1
------------------
M2T-E3 pa: show controller:
PAS unit 1, subunit 1, f/w version 3-92, rev ID 0x2800001, version 3
idb = 0x63822AD8, ds = 0x63824280, ssb=0x638245B4
Clock mux=0x30, ucmd_ctrl=0x0, port_status=0x1
Serial config=0x8, line config=0x1B0202
maxdgram=4588, bufpool=128Kb, 256 particles

   rxLOS inactive, rxLOF inactive, rxAIS inactive
   txAIS inactive, rxRAI inactive, txRAI inactive
line state: up
cable type : E3  cable, received clockrate 34107186
...
...
   Framing is g751, Clock Source is Line,   National Bit is 0
   Bandwidth limit is 34010, DSU mode 1


sh int s1/1
----------
Serial1/1 is up, line protocol is up 
  Hardware is M2T-E3 pa
  Description:
  Internet address is a.b.c.d/30
  MTU 4474 bytes, BW 34010 Kbit, DLY 200 usec, 
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation PPP, LCP Open
  Listen: CDPCP
  Open: IPCP, crc 16, loopback not set
  Restart-Delay is 0 secs
  Last input 00:00:02, output 00:00:05, output hang never
  Last clearing of "show interface" counters 18:09:31
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  30 second input rate 0 bits/sec, 0 packets/sec
  30 second output rate 0 bits/sec, 0 packets/sec
     93883966 packets input, 3782794664 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
              0 parity
     10 input errors, 10 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     145472434 packets output, 3337422460 bytes, 0 underruns
     0 output errors, 0 applique, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions
   rxLOS inactive, rxLOF inactive, rxAIS inactive
   txAIS inactive, rxRAI inactive, txRAI inactive
-------------------------------------------

-------------------------------------------
On Juniper end, I've following data:

show interfaces e3-2/0/3 extensive
----------------------------------
Physical interface: e3-2/0/3, Enabled, Physical link is Up
Interface index: 171, SNMP ifIndex: 156, Generation: 319
Link-level type: PPP, MTU: 4474, Clocking: Internal, Speed: E3,
<<<<<<<< CLOCKING HAS BEEN CHANGED TO EXTERNAL ON JUNIPER BUT SAME
BEHAVIOUR. CURRENTLY IT IS EXTERNAL.

Loopback: None, FCS: 16, Framing: G751
Device flags   : Present Running
Interface flags: Point-To-Point SNMP-Traps 16384
Link flags     : Keepalives
Hold-times     : Up 1000 ms, Down 3000 ms
...
...
Last flapped   : 2005-06-17 05:39:22 UTC (02:13:23 ago)
  Statistics last cleared: 2005-06-17 07:15:51 UTC (00:36:54 ago)
  Traffic statistics:
   Input  bytes  :               263402                    0 bps
   Output bytes  :                20779                    0 bps
   Input  packets:                 4473                    0 pps
   Output packets:                  584                    0 pps
  Input errors:
    Errors: 0, Drops: 0, Framing errors: 0, Bucket drops: 0,
    Policed discards: 0, L3 incompletes: 0, L2 channel errors: 0,
    L2 mismatch timeouts: 0, HS link CRC errors: 0, SRAM errors: 0
  Output errors:
    Carrier transitions: 0, Errors: 0, Drops: 0, Aged packets: 0
...
...
DSU configuration:
    Compatibility mode: None, Scrambling: Disabled
  E3 BERT configuration:
    BERT time period: 10 seconds, Elapsed: 0 seconds
    Algorithm: 2^3 - 1, Pseudorandom (1), Induced Error rate: 10e-0
...
...
Logical interface e3-2/0/3.0 (Index 99) (SNMP ifIndex 190) (Generation
248)
    Flags: Point-To-Point Encapsulation: PPP
    Protocol inet, MTU: 4470, Generation: 282, Route table: 0
      Flags: uRPF, uRPF-loose, Sample-input
      RPF Failures: Packets: 0, Bytes: 0
      Filters: Input: anti-spoof-downstream
      Addresses, Flags: Is-Preferred Is-Primary
-------------------------------------------        


Using above configuration, I've 10 Input Errors and 10 CRC on Cisco
interface in last 18 hours. I'm running another E3 circuit on the same Port
adaptor (PA-2E3) on the same router for last 14 months without any CRC
related problem.

Any comments? Suggestions?

Regards.


--
Shiraz Malik