Communications of the ACM

Before building the network or its components, first understand the home and the behavior of its human inhabitants.

CACM Administrator

The following letter was published in the Letters to the Editor in the December 2011 CACM (http://cacm.acm.org/magazines/2011/12/142534).
--CACM Administrator

To address the user-experience concerns raised in "Advancing the State of Home Networking" by W. Keith Edwards et al. (June 2011), we must first understand why home networks have been so successful despite the very real difficulties cited in the article. In attempting to do better for users, we might, in fact, do just the opposite. The authors recognized that developers treat networks as opaque infrastructure, which is the fundamental architectural principle that has made the Internet so generative.

Classic telecommunications is the business of providing services like the public switched telephone network, or PSTN. The Internet is a different concept, providing a common infrastructure for all services. Yet the very power of the Internet, which allows us to tunnel through legacy telecom, has also led us to accept the idea that it is just another service, like PSTN.

In the 1990s this was the plan for home computers, too. Working at Microsoft (Jan. 1995), I realized that home networking could be do-it-yourself rather than a service with a monthly bill and restrictions on what we do. I took the approach of removing complexity rather than adding solutions. Windows 98se supported the necessary protocols to "just work." This involved the requirement that the user would not have to buy any service beyond a single IP but share a single IP address. I wanted to use IPv6 so each device would have a first-class presence. But because IPv6 was not available at the time, I used Network Address Translation to share a single IPv4 address.

Rather than make the home network smarter and more cognizant of the particulars of the home, we must honor the end-to-end principle and treat the Internet as infrastructure. Developers would thus be relieved of the impossible burden of having to understand the home environment and its inhabitants. Any number of approaches could coexist.

Today's Internet protocols date from when big computers were immobile and relationships could be defined through fixed IP addresses. To preserve this simplicity, we need stable relationships for our untethered devices. This way, we could address sources of complexity rather than their symptoms.

Bob Frankston
Newton, MA