Phantom ringing

[bostech]

Hi all,

I have a customer who has an MICS 4.1 and CP150. They say that one of their lines(analog) will ring, but when they pick up no one is there. They are describing the ring as a long ring. Something they haven't heard before. Also, if they pick up the specific line and hang up they get the same ringback. It sounds like what would happen if you had centrex lines and you did a flashhook and hung up. The line would ringback because you essentially put the call on hold. The same would happen if you did the same on an analog set connected to an analog port on a switch. I'm kinda leaning to a problem from the CO. Just wondering if anyone has any ideas.

Thanks.

BTW, the system been in service for about 4 months and the problem just started. No other lines are experiencing this.

 

[bostech]

Update:

I dialed in remotely and reset the card. Didn't fix it.

 

[aragon]

An abnormal voltage on the trunk could be triggering the ringing.
Idle voltage should be roughly 48VDC
Try swapping the trunk with a working trunk on the Norstar to see if the problem follows, if it does then it is a CO problem.