CO card lockup on ACD

[renosylvia]

When the customer is put in the que and then hangs up, COT will not disconnect, (must reseat the COT to disconnect).
When the COT cards locks up the attenant can not log off. The ACD system has to be reset at lest twince a day.
User states Work mode, and call waiting will not allow user to answer.

Thank you for your assistance.

 

[smoom]

Since you used the term COT I am assuming that you have an NEC 2000. What rev. of 2000 and what type of Call Center software and Rev. are you using.

 

[pave35]

NEVER use loop start trunks with an ACD (If these are loop start lines).
In Nth America there is no disconnect supervision with copper loop start lines so what you have is quit common. The CO port is reliant upon loop current drop from the CO when the distant caller hangs up. Many times this is not passed from the CO or it is not a substantial drop and this is the problem you get. You are more than likely getting a lot of dead air messages in VM as well which is another symptom.
Your choices are changing to analog GND start or a digital circuit or you can try the carrier and see if they can assist in some way but if you can persuade them to do something your in the wrong business.
You can prove this issue by measuring the loop current on the suspected trunk while the call is in progress with a basic multimeter. You must measure DC Amps in series with either the tip or the ring lead back to the frame. During the call you will see anything from 24 ~ 45 Milliamps and when the outside party disconnects this must drop to below 20~22 Milliamps for the NEC to recognize the caller as gone.
In some other countries there is a reversal on disconnect at the distant end sent by the CO to the NEC but this is extremely rare in the US and if you can order it, it is very expensive.

 

[pave35]

BTW to test this theory try just disconnecting the cross connect for the trunk that is "locked up" without removing the CO card. This in effect is breaking the circuit to the CO and if the trunk drops (LED on CO card goes out) you know this is the issue and you can go ahead with testing with a multimeter.
Good Luck

 

[ctvi]

Pave35, would a reverse polarity make a difference? i.e. if the tip and ring are reversed would that affect anything?

http://www.ctvi.com