We're seeing a lot of errors on the serial interface. Carrier points finger at our cable, citing they were able to loop lean to the smartjack. We replaced cable between T1 CSU/DSU and smartjack w/ a brand new cat 6 cable. Now carrier is saying it became even worse, and wants us to try another cable. WTF?? Is this possible? Cat 6 not compatible w/ T1?! Can't they consider the posibility of the CSU/DSU going bad? They claimed they already reset the interface, and diagnostic came back clean... So now we're pointing finger at each other. Anyone know how I can win this battle?