ruptcy assets were picked up by Level 3 in 2002). All of these businesses seemed, in 1995, to hold great promise. Of course their long-term future was not nearly SO bright. Other companies jumped into the Internet game, of course. The single largest of the new commercial backbone ISPs ca. 1995 was probably UUNET. That company had begun in the 1980s providing any willing payer with elec- tronic mail and newsgroup access using the UUCP protocol. UUCP was a message-switching program built into Unix; its name meant "Unix to Unix Copy." Non-Unix implementations existed, but UUCP was closely linked to its Bell Labs roots. Indeed it may have been one of AT&T's more profitable inven- tions: UUCP made use of dial-up modems to exchange files periodically, increasing the parent company's long distance revenues. The trouble with UUCP was that it was entirely ad-hoc, with only manual routing. A user send- ing mail to another user would have to specify the entire path of the message, separated by "bangs": To: nodel!someothernode!ihnp4!foobar!jones UUNET offered a single hub for access, as well as a repository of files downloadable by dialing a 900 number. In the years leading up to Internet pri- vatization, it became a major player in the UUCP-based network, known as Usenet. And as Usenet discussion-group (news) traffic migrated to TCP/IP, UUNET followed. In 1995, it was acquired by Metropolitan Fiber Systems (MFS); shortly thereafter, MFS was acquired by WorldCom. Sprint also got into the business early, and for a time it had a natural advantage over BBN Planet, PSInet, UUNET, and other backbone competitors. Not only did it have experience in commercial data networking via the network that had begun as Telenet, but it also had plenty of its own bandwidth. It thus did not have to go outside and purchase bandwidth in an increasingly tight mar- ket. And in 1995, America Online acquired ANS, which it sold to WorldCom two years later. Peering and Tiering In some respects, the Internet resembles a large telecommunications network, 