When I started at my current company we were running TNCI as our PRI. No one had done a cost analyses on the product and while it was stable for the most part it was a more costly product than was available from other providers. Given our history of working with them we left the service with them for another couple years. Then we started having some very strange outages, like maybe every Wednesday at 11:58 it would cut out for two or three hours. This went on for months with them not setting up a trace until after the outage so we never got anyplace. Finally I contacted our last mile provider and had them look into it, found we ran into an old leaky shed and replaced some cards no more outages. By then the damage was done and the relationship was tarnished. we began the process of finding a new PRI provider.