The problem the FCC is solving is: Person is in an emergency, they pick up the closest device and dial 911. That needs to go through, complete with location i

The problem the FCC is solving is: Person is in an emergency, they pick up the closest device and dial 911. That needs to go through, complete with location information. The specific triggers for the rule were old-landline handsets plugged into VoIP boxes routing through carriers that didn't have E911 connections. A child would pick up the phone, dial 911, the other end wouldn't have the address, and the child wouldn't know it either. This rule would appear to include _anything_ capable of making a call, including things that don't look like phones (tablets). That is mixed with the desire for carriers (and others) to intercept long-distance and other calls (no signal, cheaper rates, etc). Microsoft used to sell something which would automatically intercept and redirect calls to other private numbers off of the cell network. This allowed higher quality codecs and lower costs. If the handset maker only supports 911 when there is a cell signal, then this runs afoul of the FCC rule. The handset could be used in a location with wifi (but no cell signal), and be used to make calls. Someone picks up that handset, tries to dial 911 and is denied. Microsoft, since they're a VoIP provider, needs to deal with E911. Google, needs to be fault-tolerant in the 911 dialing path and have good fallbacks.