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New Member

To many input CRC error on T1 int.

I am getting too many errors(just in 20 minutes) on S0/0 int. The user is complaining of slow connection.. What is the problem?

MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,

reliability 234/255, txload 3/255, rxload 58/255

Encapsulation FRAME-RELAY IETF, loopback not set

Keepalive set (10 sec)

LMI enq sent 380, LMI stat recvd 377, LMI upd recvd 0, DTE LMI up

LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0

LMI DLCI 0 LMI type is ANSI Annex D frame relay DTE

Broadcast queue 0/64, broadcasts sent/dropped 0/0, interface broadcasts 0

Last input 00:00:03, output 00:00:00, output hang never

Last clearing of "show interface" counters 01:03:24

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 353000 bits/sec, 36 packets/sec

5 minute output rate 24000 bits/sec, 20 packets/sec

148534 packets input, 173672761 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

19484 input errors, 11414 CRC, 5780 frame, 0 overrun, 0 ignored, 2290 abort

94188 packets output, 21767985 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up

  • WAN Routing and Switching
6 REPLIES

Re: To many input CRC error on T1 int.

The output indicates that the reliability is not 100% healthy (234/255), this suggests that you possibly have a physical issue or clocking issue between the CE and the NTU.

Ordinarily the reliability should be 255/255, the fact that it is not will undoubtedly contribute the input errors and CRC that you are experiencing.

Either report the fault to your carrier/telco, or initially try replacing the cable.

HTH

Allan.

Hall of Fame Super Silver

Re: To many input CRC error on T1 int.

Hello Manjinder,

there is clocking or cabling problem

First of all, have someone resets the external CSU on both ends of the link.

If this doesn't slove Contact the WAN provider and have them perform the classic loopback tests

Hope to help

Giuseppe

New Member

Re: To many input CRC error on T1 int.

Hai,

Try to take a local loop from modem that will confirm router interface,V.53 cable.If this is clean ask TElco to provide loop

from next node (Mux RSU).(before this reset the modem/CSU/Dsu ..clear the counters and see reliablity is comming to 255/255 also check wheather the errors are increasing rapidly ....

in this case as Allan,Giuseppe mentioned seems to be L1 issue.

(19484 input errors, 11414 CRC,)

ujil

New Member

Re: To many input CRC error on T1 int.

I changed the cable going to NTU. Rebooted the router.

ALso called my provider for looptest. Their results are -ve , the error % kind of improved little bit but errors are still there..

What should be my next step?

appreciated

New Member

Re: To many input CRC error on T1 int.

You can check to see what the keealive variable is on the other end of the connection

Keepalive set (10 sec) at local device,sometimes uncorrect keepalives at both ends can cause this issue.

Keealive local =10

Keepalve remote= 10

Re: To many input CRC error on T1 int.

hi,

i just had a similar problem not too long ago. try show controllers t1 and specifically look at 'slip' errors that are incrementing on each interval. we've done looptest with telco and they corrected the problem with clock config on their side. you should press them for checking their configurations.

my t1 before:

T1 0/1/1 is up. (Line Looped (inband CSU code)) (Line Loop by Remote)

Applique type is Channelized T1

Cablelength is long gain36 0db

Description: "Slot 1 Port 1 VWIC2-2MFT T1 Card"

Receiver has no alarms.

alarm-trigger is not set

Soaking time: 3, Clearance time: 10

AIS State:Clear LOS State:Clear LOF State:Clear

Version info Firmware: 20071011, FPGA: 13, spm_count = 0

Framing is ESF, Line Code is B8ZS, Clock Source is Line.

CRC Threshold is 320. Reported from firmware is 320.

Data in current interval (714 seconds elapsed):

0 Line Code Violations, 1182 Path Code Violations

715 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 11 Degraded Mins

715 Errored Secs, 350 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

t1 after clock was corrected at provider:

T1 0/1/0 is up.

Applique type is Channelized T1

Cablelength is long gain36 0db

Description: "Slot 1 Port 0 VWIC2-2MFT T1 Card"

No alarms detected.

alarm-trigger is not set

Soaking time: 3, Clearance time: 10

AIS State:Clear LOS State:Clear LOF State:Clear

Version info Firmware: 20071011, FPGA: 13, spm_count = 0

Framing is ESF, Line Code is B8ZS, Clock Source is Line.

CRC Threshold is 320. Reported from firmware is 320.

Data in current interval (477 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

Data in Interval 1:

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

Data in Interval 2:

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

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