Re: Call Manager 6.1 PSTN calls randomly disconnected

andy_4578 · ‎02-16-2011

Just wondered if anyone can advise the best approach to diagnose random pstn call disconnects.

It's happening quite alot, but doesnt happen to all users at once just random users.

We have a Unified Communications MCS server running linux O/S and call manager version 6.1 business edition. The gateway is a 2811 router using H323.

Any help would be good

Thomas Dominic · ‎02-16-2011

Hi Andy,

How is the connection to the Telco, is it a T1. If so we can start diagnosing this problem with running the following debug on the G/W

debug isdn q931

we then need to log this onto the router buffer so that we can pull them later

Steps to enable proper logging

Router#configuration terminal

Router(config)#no logging console

Router(config)#logging buffered debugging (maximum possible)

Router(config)#service sequence

Router(config)#no logging rate-limit

Router(config)#exit

Router#

Regards

Thomas

Please rate helpful posts

andy_4578 · ‎02-16-2011

Hi Thomas

It's the UK version of a T1 so its an E1 but same rules apply. I've enabled debug isdn q931 although im not sure the buffer on the router will be large enough as the problem may only occur once every couple of days, other times it can be 4 drops in one day.

Is there a way to send just the isdn q931 debugs to a syslog?

Thanks

Andy

Thomas Dominic · ‎02-16-2011

It should be enough to hold atleast a days worth of debugs, periodically clear the logs if the issue does not occur.

cisco# clear log

Regards

Thomas

andy_4578 · ‎02-16-2011

Just turned syslog on sending the traps to an internal syslog server at debug level which killed the router.

Im guessing that was all debug messages and not just isdn q931??

andy_4578 · ‎02-17-2011

The logs are only showing the following info.... Which doesnt give any disconnect reason?

000100: *Feb 16 16:54:36.255: %ISDN-6-DISCONNECT: Interface Serial0/3/0:21 disconnected from 07540542048 , call lasted 29 seconds
000101: *Feb 16 16:54:37.363: %ISDN-6-CONNECT: Interface Serial0/3/0:18 is now connected to 08448488144 N/A
000102: *Feb 16 16:54:38.547: %ISDN-6-CONNECT: Interface Serial0/3/0:19 is now connected to 07738727130 N/A
000103: *Feb 16 16:54:39.027: %ISDN-6-CONNECT: Interface Serial0/3/0:20 is now connected to 01865274920 N/A
000104: *Feb 16 16:54:39.827: %ISDN-6-CONNECT: Interface Serial0/3/0:0 is now connected to 1604628979 N/A
000105: *Feb 16 16:54:43.363: %ISDN-6-CONNECT: Interface Serial0/3/0:18 is now connected to 08448488144 N/A
000106: *Feb 16 16:54:44.583: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/3/0:0, changed state to up
000107: *Feb 16 16:54:44.635: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/3/0:18, changed state to up
000108: *Feb 16 16:54:44.639: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/3/0:20, changed state to up
000109: *Feb 16 16:54:45.027: %ISDN-6-CONNECT: Interface Serial0/3/0:20 is now connected to 01865274920 N/A
000110: *Feb 16 16:54:45.827: %ISDN-6-CONNECT: Interface Serial0/3/0:0 is now connected to 1604628979 N/A
000111: *Feb 16 16:55:01.803: %ISDN-6-CONNECT: Interface Serial0/3/0:21 is now connected to 123 N/A
000112: *Feb 16 16:55:05.411: %ISDN-6-CONNECT: Interface Serial0/3/0:21 is now connected to 123 N/A
000113: *Feb 16 16:55:05.411: %ISDN-6-DISCONNECT: Interface Serial0/3/0:21 disconnected from 123 , call lasted 3 seconds
000114: *Feb 16 16:55:12.283: %ISDN-6-DISCONNECT: Interface Serial0/3/0:19 disconnected from 07738727130 , call lasted 39 seconds
000115: *Feb 16 16:55:26.827: %ISDN-6-DISCONNECT: Interface Serial0/3/0:20 disconnected from 01865274920 , call lasted 47 seconds
000116: *Feb 16 16:55:29.583: %ISDN-6-CONNECT: Interface Serial0/3/0:19 is now connected to 01933624249 N/A
000117: *Feb 16 16:55:30.303: %ISDN-6-CONNECT: Interface Serial0/3/0:21 is now connected to 01642754000 N/A

Sebastiandm_2 · ‎02-17-2011

Can you clear the counters on all your interfaces monitor them for errors/CRC`s

show inter serial 0/3/0:15

Cheers

andy_4578 · ‎02-17-2011

This is the output. (Router has been up 24 hours)

...

Serial0/3/0:15 is up, line protocol is up (spoofing)
Hardware is DSX1
MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Last input 00:00:03, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
     Conversations 0/1/256 (active/max active/max total)
     Reserved Conversations 0/0 (allocated/max allocated)
     Available Bandwidth 48 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
     14323 packets input, 94657 bytes, 0 no buffer
     Received 0 broadcasts, 1 runts, 0 giants, 0 throttles
     2 input errors, 2 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     14327 packets output, 110227 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out
     3 carrier transitions
Timeslot(s) Used:16, SCC: 0, Transmitter delay is 0 flags

andy_4578 · ‎02-17-2011

Problem just happened again in quick succession and generated 2 additional input errors and 2 additional CRC errors, all users got cut off, aparently all users have always been cut off .....

Serial0/3/0:15 is up, line protocol is up (spoofing)
Hardware is DSX1
MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Last input 00:00:00, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
     Conversations 0/1/256 (active/max active/max total)
     Reserved Conversations 0/0 (allocated/max allocated)
     Available Bandwidth 48 kilobits/sec
5 minute input rate 0 bits/sec, 3 packets/sec
5 minute output rate 0 bits/sec, 3 packets/sec
     19411 packets input, 136351 bytes, 0 no buffer
     Received 0 broadcasts, 1 runts, 0 giants, 0 throttles
     4 input errors, 4 CRC, 0 frame, 0 overrun, 0 ignored, 2 abort
     19415 packets output, 160069 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out
     7 carrier transitions
Timeslot(s) Used:16, SCC: 0, Transmitter delay is 0 flags

Giovanni Ceci · ‎02-17-2011

Could you do a show controller e1. This command (according to the below article) will show you the following:

Statistics about the E1 link. If you specify a slot and a port number, statistics for each 15 minute period will be displayed.
Information to troubleshoot physical layer and data link layer problems.
Local or remote alarm information, if any, on the T1 line.

It could possibly be slips are present on the E1 line. Could you paste the output of the above command? I'm curious to see

Reference Link: http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00801095a3.shtml#topic2

Thanks,

neocec

andy_4578 · ‎02-18-2011

Output from "sh controller e1"....

Voice_Gateway#sh controller e1
E1 0/3/0 is up.
Applique type is Channelized E1 - balanced
No alarms detected.
alarm-trigger is not set
Version info Firmware: 20071009, FPGA: 20, spm_count = 0
Framing is CRC4, Line Code is HDB3, Clock Source is Line.
CRC Threshold is 320. Reported from firmware is 320.
Data in current interval (597 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)
     27 Line Code Violations, 5970 Path Code Violations,
     1 Slip Secs, 1 Fr Loss Secs, 11 Line Err Secs, 0 Degraded Mins,
     1 Errored Secs, 0 Bursty Err Secs, 12 Severely Err Secs, 11 Unavail Secs

Volodymyr Morskyy · ‎02-18-2011

That is what cisco output interpreter returns:

WARNING: This controller appears to have excessive framing errors (5970) in
the last 24 hours.
TRY THIS: Clear the counters and continue to monitor the show controller output.
If problems persist, confirm the framing with the carrier.

WARNING: This controller appears to have excessive line errored seconds errors,
(11) in the last 24 hours.
'Line errored seconds' are the number of 1-second intervals in which a Line Code
Violation occurred.
TRY THIS: Clear the counters and continue to monitor the controller using the
'show controller' command. Ensure that the equipment on the remote end of the
75 ohms coax cable sends a E1 signal with line code. Check the 75 ohms coax cable
integrity by looking for breaks or other physical abnormalities in the cable.
Replace the cable if necessary. Insert an external loopback cable into the port.

WARNING: This controller appears to have unavailable seconds errors, (11) in the
last 24 hours.
'Unavailable Seconds' are the number of 1-second intervals in which the controller
was down.
TRY THIS: Clear the counters and continue to monitor the controller using the
'show controller' command. Ensure that the local interface port configuration
corresponds with the far-end equipment configuration. Identify the alarm on the
local end and execute the actions as suggested. Consider inserting an external
loopback cable into the port.

Check this page: http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00800f99bb.shtml

Giovanni Ceci · ‎02-18-2011

Looks like you're getting Line Code and Path Code violations. According to this same article, you should contact your ISP.

http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00800f99bb.shtml#linecode

HTH,

neocec

andy_4578 · ‎02-18-2011

Logged a fault with British Telecom, who have advised me an engineer has been to the local exchange and fixed a fault. But they wont tell me what the fault was.

Volodymyr Morskyy · ‎02-18-2011

Mark useful answers and close the thread.