I'm pursuing the theory that this is a behavior not inside my Panasonic switch or even in my home network but I can't completely eliminate that. I'm pursuing the theory that this is a kind of "echo" that is theoretically possible in a packet-switched network like an internet although eliminated by network HW and SW. It's the theory that packets travel outward on multiple linkages across the internet seeking the same destination but normally get killed once a connection if found. Like VOIP, you're transmitting in packets where multiple duplicates of the packet can exist at the same time for a limited time. I believe what has happened is we've switched from circuit switching to packet switching right?
An alternative theory would be that the "echo" is being generated inside my local network but I don't like that as much because (1) I cannot duplicate this on calling my call phone from my Panasonic lines and (2) it happens as much as 1-2 minutes after the call is placed and while the call is still in progress.
