I have a pri from the telco that is not slipping but about 3 weeks ago the PRI loop started to experience frame losses, no slips etc but frame losses just like this person's thread thread798-1564761 . My system is a CSE 6.0 system with one PRI but exact same symptoms. I have changed out the pairs to the server room, the card, I moved the TMDI to a new cabinet so I have done everything I can think of. Any suggestions would be appreciated.. telco of course says it's not their issue.