Solution 1.
Busy and release the PMS-link and Primary CDR link
Verify Link comes back up.
status pms-link
PMS LINK STATUS
Physical Link State: up
Protocol State: up
Maintenance Busy? no
Data Base Swapping? no <-- back to "no" after link busy/release
status cdr-link
CDR LINK STATUS
Primary Secondary
Link State: down CDR not administered
Number of Retries: 999
Date & Time: 2015/12/14 8 :30:39 0 /0 /0 0 :0 :0
Forward Seq. No: 0 0
Backward Seq. No: 0 0
CDR Buffer % Full: 8.00 0.00
Reason Code: CDR connection is closed
Solution 2
Reboot IOLAN device to restore link connectivity
after IOLAN reboot
status cdr-link
CDR LINK STATUS
Primary Secondary
Link State: up CDR not administered
Date & Time: 2015/12/17 11:27:29 0 /0 /0 0 :0 :0
Forward Seq. No: 0 0
Backward Seq. No: 0 0
CDR Buffer % Full: 0.00 0.00
Reason Code: OK
status pms-link
PMS LINK STATUS
Physical Link State: up
Protocol State: up
Maintenance Busy? no
Data Base Swapping? no
Solution 3
Replace defective CLAN board.