His Napster's Voice
David G. Post
By now, everybody knows the Napster story. Napster, a clever little Internet application invented by a 19-year-old college dropout right out of central casting, is quite simple. It works, more or less, as follows. You download the Napster software. You run the software on your computer. It scans your hard disk and compiles a directory of the names of the music files it finds there. It then sends that directory—not the files themselves, just the list of file names— back to Napster's “home” computer, the Napster server, where it is placed into a database, along with the directories of all of the other Napster users who have gone through the same process (70 million or so at its peak).
The next time you (or any of the 70 million) log onto the Internet, your computer, in addition to doing whatever else it is doing, sends a message to the Napster server: “User John Doe here—I've just logged on to the Internet, and my ‘Internet Protocol address’—the number my Internet Service Provider has assigned to me so that I can send and receive messages over the Internet—is [255.255.4.11].” 1 The Napster server updates the database with this information, so that, in addition to the names of the music files on each Napster user's hard disk, it now contains information about whether each user is, or is not, currently logged on, and the Internet address of all users who are currently online.
So far, so good. If you then find yourself, on some dark and lonely night, desperate to hear, say, Bob Dylan's version of the Stanley Brothers' classic “Rank Stranger,” you send a query to the Napster server: “Does your database list any machines that have a copy of this song? If so, can you please provide me with the list of those that are currently logged onto the Internet—with their IP addresses, if you don't mind?” When the server sends you back that list, the Napster software conveniently lets you send a message directly to any of those machines—because you have their IP addresses you