802.11n: A Survival Guide

Chapter 7. Planning an 802.11n Network

Ethernet is dead.

—Friedrich Nietzsche, had he been a network administrator instead of philosopher

On a very long airplane flight when writing this book, I decided that you have a special affinity for things that you recall when you “came of age.” I can’t think of a good reason why I find the electro-pop music of the 1980s a guilty pleasure, or why I feel sad that Ethernet is slowly dying. Both eighties music and Ethernet correspond to my coming of age in both fields. I can trace my career in networking to my first experiences with Ethernet, and I was building LANs well before every home had one.

Regardless of my feelings on the matter, Ethernet is dying as an access technology. Given the choice, most users (especially younger users!) will connect to a wireless network instead of digging for a cable and finding an Ethernet port. That is, if they even know what an Ethernet port looks like. In a striking illustration of the point, a university network administrator once told me that out of the thousands of sessions in the university library in the previous semester, less than 100 unique MAC addresses had been detected on the library’s wired Ethernet network. It’s a good bet that many students now entering universities have never had to deal with Ethernet in the same way that I did.

With 802.11n, performance has reached the stage where it is acceptable as a wire replacement. Home networks can happily run on Fast Ethernet, with 802.11n easily exceeding ...