Single call to landline, only 2 sec long. So many single ring calls with online blocker that it seems likely my spammers are using brand new numbers to test how they can get through. So I shut off all blocking and am forwarding all incoming calls to "not in service" until traffic diminishes, or I will change numbers or drop landline altogether. With all incoming calls forwarded - outgoing calls work fine and incoming calls are still logged. So I really don't miss anything, appreciate the restored tranquility of home, and snicker at the the thought of telemarketers listening to my "not in service" message.