To change the Call Coverage Timer in the SV8100
Go to Program 20-31-03 Timer Class Timer Assignments
Select the Class you wish to use for your Extension or Virtual Ext.ie Class 2-Change the Call Coverage Timer to the Time you wish the call to delay before ringing the next group of phones.
Go to Program 20-29 and make sure your Ext. or Virtual Ext. is in the Correct Class of Service ie: 2 as in the above example