D-Channel Dropping

[msteeler]

So I have a site with a voice gateway router and the CUCM is located at a centralized location. The LEC has seen the D-Channel drop but says its our equipment not theirs. I had them come out and test from the NIU and they say they have no errors on their side. In RTMT I see the D-channel dropped again last night and returned to service 2 minutes later. What can I look at on my side to start ruling out my equipment? I going to swap out the VWIC today and change the cabling between the NIU and router, but is there anything else I can try? I think this is a clocking issue but I’m not sure how to tell if it’s the LEC or us.

Any errors you see below are new as of yesterday. Thanks


T1 0/0/0 is up.
Applique type is Channelized T1
Cablelength is long 0db
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 FPGA Rev: 08121917, FPGA Type: PRK4
Framing is ESF, Line Code is B8ZS, Clock Source is Line.
CRC Threshold is 320. Reported from firmware is 320.
Data in current interval (418 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
Total Data (last 24 hours)
0 Line Code Violations, 2 Path Code Violations,
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
2 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

#sh int s0/0/0:23
Serial0/0/0:23 is up, line protocol is up (spoofing)
Hardware is DSX1
MTU 1500 bytes, BW 64 Kbit/sec, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, crc 16, loopback not set
Keepalive set (10 sec)
Last input 00:00:06, output 00:00:06, output hang never
Last clearing of "show interface" counters 2d16h
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 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
18684 packets input, 147016 bytes, 0 no buffer
Received 0 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
3 input errors, 3 CRC, 0 frame, 0 overrun, 0 ignored, 1 abort
18686 packets output, 146696 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 unknown protocol drops
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions

 

[gnrslash4life]

Clocking issues should have more errors. Also, since its set to line then you should be fine. I think you are starting a good place. Start with the basics. Replace the cable. Reboot the router before you go and replace the vwic. I have seen DSP's get funky and do strange things to PRI's and a reboot cleared it up.

Also, do you have debugging of any kind running to see what its throwing out at the time it drops?

Certifications:
A+
Network+
CCENT
CCNA Voice

 

[msteeler]

I have the below debugging on although I haven't seen the d-channel drop while I'm here. The one last night shows 3:30am. If I do a sh log there's nothing there.

The following ISDN debugs are enabled on all DSLs:

debug isdn error is ON.
debug isdn q921 is ON. (filter is OFF)
debug isdn q921 detail is ON.

 

[gnrslash4life]

Turn on Q931.

Certifications:
A+
Network+
CCENT
CCNA Voice

 

[msteeler]

Thanks, I tuned on Q931 last week. The d-channel had not dropped since last week. I looked at RTMT this morning and saw the d-channel dropped last night at 11:30pm. I did a sh log on the VG router... nothing. I checked the controller.... no errors. I checked the serial int and I have 1 input error, 1 CRC, and 1 abort. I'm guessing that's because of the d-channel drop?? Doesn't seem like enough errors to cause it to drop.

Do you only see debugging as something happens or is there a log? Thanks