Not sure what release your system is,
but a patch mplr27770 X21 4.50W was issued to cure the following fault that had cause 44.
Problem Scenario :
QSIG EGF4 PRI link using DPRI NT5D97AD and MSDL d/bd NTBK51AA to a third-party IVR system
A real-time monitoring utility on the IVR system causes an application to crash and calls are then rejected with cause 44 (requested channel not available). At this point the M1 puts the B-channel into LCKO and tries all other channels in turn, until all are in a LCKO state. The DCH is still enabled and active.
.............Now reboot the IVR system (or disconnect the PRI cable).
Expected Response:
M1 to continue call processing normally
Actual Response :
Lots of PRI358 messages produced and Call Registers quickly disappear from the Idle queue until all are used up (this takes less than 2 minutes) and call processing stops
Recovery Process :
1) Disable the DCH on the M1 (if you are quick enough) or, if not
2) Manual INI of the M1
Patch 27770_1 written to fix the problem
FULL PROBLEM DESCRIPTION:
Loads of PRI358 message is causing the switch to eat away the Call registers, this issue is triggered on site and happens 100 % under the following conditions.
Meridain Swith connected directly to an IVR system over a Qsig PRI connection. Under certain condition the IVR system fails to respond to an i/c SETUP message due to faulty conditions of the IVR. In response it will send an 0_CC_REJECT message with cause of 44 (.PRA_NO_REQ_CH). Once the Meridian receives this message it will put the channel into lock-out as normal. When all 24 B’channels have been locked out, if the PRI cable is disconnected or IVR server rebooted, then the switch will print loads of PRI358 messages on the TTY.
We have the CRSTART logs following on from the problem that shows loads of Callregisters stuck in MAINPM( .SPECIAL) and AUXPM (.DCH_MAINT).
Set-up
1) Node A: Meridian Switch OPT (61) running x210450w, pp4.
a) Receives i/c pstn call to IVR.
b) Qsig pri connection directly to an IVR system.
2) IVR system to handle i/c call connected to Node A over a Qsig (pri) connection.
ACTION
1) Assume the IVR system has a fault and is unable to respond to a call.
2) Make any type of call to reach the IVR from Node A.
3) Once all B channels are locked-out, due to receiving a O_CC_REJECT message with Cause (44). Disconnect the PRI cable or Re-boot the IVR.
EXPECTED RESULTS:
1) Print loads of PRI358 messages on the TTY, But no Callregisters should be stuck!!
ACTUAL RESULTS:
1) Print loads of PRI358 messages on the TTY and loads of Callregisters are stuck in
MAINPM( .SPECIAL) and AUXPM (.DCH_MAINT).
This causes the switch to slow down and will eventually halt. The only way out is to re-boot the switch.
IMPACT OF PROBLEM: Loss of service
SYMPTOMS EXHIBITED:
DCH 24 UIPE_OMSG CC_SETUP_REQ REF 0000065F CH 24 22 TOD 12:27:43 CK 5BD8FB19
PROGRESS: INTERWORKING WITH A PUBLIC NETWORK
PROGRESS: CALL IS NOT END TO END ISDN
CALLED #:1225 NUM PLAN: PRIVATE TON: ESN CDP
DCH 24 UIPE_IMSG CC_REJECT_IND REF 0000065F CH 24 22 TOD 12:27:43 CK
5BD8FBCC
CAUSE: #44 - REQ CIRC/CHAN NOT AVAILABLE
ERR9032 24 22 12:27:43 23/01/2009
PRI cable is disconnected or IVR server rebooted,
DTA203 24 4 2
DTA203 24 4 1
PRI358 24 124014709 24 124014709
PRI358 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 12401470o9
PRI358 24 124014709 24 124014709
PRI358 24 124014709 24 124014709
PRI358 24 124014709
All the best
Firebird Scrambler
Meridian 1 / Succession and BCM / Norstar Programmer in the UK
If it's working, then leave it alone!.