Rest Line

Dear All,

I am using SR 6.0 with DM3 and Windows 2003 server.
I have V600BTEP PCI Board and our Lines  are 2 E1
Our's  is IVR InBound call application is working fine

but after each 15 Minutes line 2 E1 (2) do Rest and write event type=0817 and unlock Channel

and drop all calling in line 2

So, Please suggest me regarding this error.

Thanks and Regards,

Ayman