This is a problem in the last few days. TSU120 T1 split data and voice on a P to P . The 120 shows slips on DSX, but no errors on the CSU side.This is only at one end point. Nothing has changed at both ends into both MICS.
I will replace the DTI card in the MICS Monday, but
I am not really sure about that.

Could tel co have a problem that only shows up on the voice side ? Or the 120 is not passing timing to the dsx correctly.

Hard to believe that this customer would have two bad TSU 120's in six months after no other Adtran failures in twenty years !!!

We just had this issue last week. Verizon techs came to site and said "Its a timing issue in your PBX". I was able to show them that we clock from them and he retested at the smart jack again. Then he had the frame slips also. Come to find out it was the card in the Smart Jack. They replaced it and we have been running clean since.

Adtran's tech support is very helpful. They can help you run diagnostic testing from the 120. With their help I was able to convince the computer guy that his router was bad.

I have Adtrans's support number and plan to call them Monday from the customer. I hope they have someone that knows the 120, as it's kind of old.

They will have a Tech call you back and they will know the 120. I called the other day on the issue above with a question on a 120e

This morning the errors where no longer happening.
Guess the carrier was involved somehow.