I have a customer who has an IP Office system which I took over managing. I've installed and maintained many of these systems in the past but I've run into something I've never seen before. Customer has two cards each with trunk daughter cards. The system has 5 trunks and I get random trunk out of service alarms on all 5 of them. The customer originally had only 3 lines but they were still spread over both cards when I took over the system. They would call every couple of days usually saying they couldn't get an outside line or calls weren't coming through temporarily. Best I can tell it was usually when a couple of people were on the phone and then the last line would go out of service. When I go look at the system everything seems to be back working again as it should. But I notice several alarms every day. Originally I thought maybe there was something in the configuration that was weird since I didn't set it up and there were things done in ways that I wouldn't have done them. So I bit the bullet and rebuilt the whole config from scratch. Problem still occurs. I've talked with the phone provider and they have changed equipment for me but have said all along everything is working properly on their end. I've done many systems hooked to this providers lines in the past and never had any issues before. At one point I thought that maybe there was a bad card but I don't see two cards being bad. Is there something I'm missing?