VG 2951 with 15.3(1)T: continuous ISDN Q.921 messages

[raziel78kain]

Hello,

we have a CUCM that uses a Cisco 2951 with IOS c2951-universalk9-mz.SPA.153-1.T.bin as a Voice Gateway (in SIP).

We have noticed on the router (by the command "debug isdn q921") that the messages in attachment appears continuously.

Here's a sample:

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May 25 2013 09:41:08 LEGALE: ISDN Se0/0/0:15 Q921: User RX <- REJ sapi=0 tei=0 nr=33

May 25 2013 09:41:08 LEGALE: ISDN Se0/0/0:15 Q921: S7_REJ_RNR_RR: REJ received Nr 33 VA = 33, VS = 33

May 25 2013 09:41:09 LEGALE: ISDN Se0/0/0:15 Q921: User RX <- REJ sapi=0 tei=0 nr=33
May 25 2013 09:41:09 LEGALE: ISDN Se0/0/0:15 Q921: S7_REJ_RNR_RR: REJ received Nr 33 VA = 33, VS = 33

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Is it an issue? If yes, how can it be solved?

Furthermore, can it be the cause of a poor quality on some calls that users complain?

TIA and regards.

[paolo bevilacqua]

Post "show controllers E1".

[raziel78kain]

E1 0/0/0 is up.

  Applique type is Channelized E1 - balanced

  Description: ISDN PRI N.1 - Primary PRI PSTN *********

  No alarms detected.

  alarm-trigger is not set

  Version info FPGA Rev: 08121917, FPGA Type: PRK1

  Framing is CRC4, Line Code is HDB3, Clock Source is Line.

  International Bit: 1, National Bits: 11111

  Data in current interval (91 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 69 15 minute intervals):

     17 Line Code Violations, 0 Path Code Violations,

     0 Slip Secs, 1 Fr Loss Secs, 1 Line Err Secs, 0 Degraded Mins,

     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 1 Unavail Secs

[paolo bevilacqua]

No errors. You can check serial 0/0/0:15, but likely no errors there either, so these REJs are a bit strange.

[raziel78kain]

Serial0/0/0:15 is up, line protocol is up (spoofing)

  Hardware is DSX1

  Description: description ISDN PRI TO PSTN *********

  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 00:00:00, output 00:00:06, 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: 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

     249314 packets input, 1001404 bytes, 0 no buffer

     Received 0 broadcasts (0 IP multicasts)

     0 runts, 0 giants, 0 throttles

     1 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

     6592 packets output, 30577 bytes, 0 underruns

     0 output errors, 0 collisions, 4 interface resets

     0 unknown protocol drops

     0 output buffer failures, 0 output buffers swapped out

     1 carrier transitions