We have a CIX 670. About 2 months ago we had a contractor upgrade the processor to allow IP phones and VOIP. Through the process the contractor had to manually program the new processor. We had some issues that had to be tweaked with the flex button etc... The biggest problem was the paging. We have three paging phones (ext 199, 299, 399). They seem to work fine for the overhead speakers. However when the High School or Elementary do announcements they would just stop/ cut out on the phones in the rooms. Now with that said it is not always consistent with all the phones doing it. It happens with different phone we page from. I have deleted the extension out of the different paging groups and re-adding them. I do have emanager and I do some minor program such as changing extensions. I have a service call in to the contractor. Its just got me baffled.

You have your starting point right there.