Dear all experts,

I have tie line E1 PRI with NEC PBX. There were a few call that active for very long period up to 2 Weeks. I wonder why is this happening with E1 connection, i know it is very common to find this problem on FXO port. I looked into Controller E1 detail and found no clock slip error. Show int s0/0/0:15 also found no error. Could any one tell me what could be the problem here.

Please see the Logg file in the attachment.

Thanks so much!

Prachaya