Have a customer with a MICS (7.1 SW) and a CallPilot. They have one CI trunk card, and use all 4 lines on that card. They informed me that randomly they will hear a click or clicking on the lines. Have heard this on multiple extensions. I checked the lines coming into the system and couldn't find any faults. Using my test set, I tapped into an active call and monitored the conversations. I could hear no clicks but the receptionist and others in the office swear its there.

I swapped the trunk card with a known spare and rebooted the KSU. No change. They say they are still randomly hearing a click on the line(s). I am having them open a ticket with their provider (CenturyLink) just to verify that the lines are ok, but I suspect that they will find no trouble.

Anyone ever come across anything similar?