Option 11c to 5ESS on pri that has slips. 1 pri is connected to a lab GMSC/PCR card E-1 this is the clock source CC comes right up stay's green. 1 pri is option 11c to DCOSS. I moved the cable from the 5ess to any other pri and the slips follow! I have used euro, ess5, e403 for IFC on the pri that's slipping in LD17!