The latest-written tutorial in the 4th Edition of the Network Tutorial ran in March 2000. Since that date we have published several tutorials on optical networking, voice-over-IP protocols, and local loop technologies technologies that have been closely associated with carriers and telecom service providers, who in turn were betting on rapidly growing demand generated by the Internet and so-called e-commerce. These pieces have become perhaps less immediately crucial to our readers as the telecom bubble bursting followed the dot-com bubble bursting and the market for these technologies shriveled.

On the other hand, many of the tutorials (along with Network Magazine as a whole) over the last three years have focused on network security, a trend that began well before the attacks of September 11th, 2001, got everyone thinking about security. Which is not to say that there are technology solutions to the threat posed by terrorists like Al Qaida, or that national security has anything but a tangential relation to network security despite all the dubious stories about terrorist hackers from China, Iraq, or evildoer nations elsewhere. Major security threats to the networks of 2003 still seem to arise primarily from disgruntled employees, thrill seeking vandals with time on their hands, and criminals who want to take economic advantage of the anonymity and remote-control characteristics of The New Public Network.

The other area of growth over the past three years has been wireless networking. Wireless LANs in particular have continued to spread rapidly in recent years when most other...