Call Group is probably one of the most used feature. As shown on the picture above, 4 phones (ext. 1001, 1006, 1009 and 1018) were assigned to a call group called “Sales”. When you customer calls to the sales group, all phones that are member of that group will ring. Alternately, one phone can ring for a specified duration of time and then the call will automatically go to the next member of the Sales call group.