BCM50 Phantom Ringing

[kh3572]

I have a BCM50 that was installed 4-5 months ago. There are two locations networked via voip with no problem. Site A has a PRI circuit that site B using for making and receiving calls. About 2 weeks ago the customer started complaining of phantom ringing. On two different extensions, a call rings in on the intercom, display never changes from time and date, once they lift the receiver the display shows their number but nobody is on the line. When they hang up the phone is starts ringing again and will continue the same scenrio 4-5 times before it stops. I haven't been able to duplicate the problem once I get on site nor has the customer, but they have complained several times about this same issue so I have to believe that it's happening.

Any ideas/suggestions?

 

[Bitonti]

I'm having a similar issue with a BCM 400 3.7. Customer says it rings once and nothing happens. This happens about 3 or 4 times a day on about 5 extensions.