If you thought that the digital TV transition, with its billion-dollar coupon program for converter boxes, was a migration nightmare, wait until it's time for the phone system to dump its legacy circuit-switched system and move to an all-IP communications network. That day could be coming sooner than you think; the Federal Communications Commission has just requested comment on its planning for the transition.

As the document notes, we've been through such transitions before on a smaller scale, including the DTV transition in mid-2009 and the earlier switch from analog to digital mobile networks. "While each transition is different, policy has played an important role in ensuring consumers were protected from loss of essential services and were informed of the choices presented by the transition," says the FCC.

The agency isn't yet ready to announce a "glide path" to an all-IP network, but it does want to start assembling knowledge about what's likely to break and how existing programs like the FCC's special phone services for the deaf will make the transition.

Telecom carriers increasingly run IP backbones and last-mile IP access to offer Internet service to home and business users. Cable and telcos like AT&T and Verizon have for years tried to move people in the direction of IP-delivered services, especially for phone service (when it comes to TV service, AT&T is the main IP-only player in the US), but huge sections of the country still rely on Plain Old Telephone Service (POTS) using circuit-switched services.

The transition to a fully packet-switched IP network, when it comes, will be "market led," but the FCC is already starting to think about how to protect consumers from the "loss of essential services" and how to inform them "about the choices presented by the transition." If you thought showing grandma how to hook up a digital-to-analog converter box was tricky, wait until you install her IP phone or plug her ancient rotary dial into a router.

Given that voice services now make up only a fraction of the data traveling across the total US communications networks, it certainly makes little economic sense to continue supporting two separate systems But, as with anything that has grown up for a century, pulling the plug requires plenty of planning.

Just imagine the education campaign that tries to explain to Americans that their phone calls will now be subject to the latency, jitter, and network bandwidth issues that come with VoIP—and just wait until the entire issue of voice communications intersects with network neutrality concerns.