loyed as a bridged or routed backbone, using Ethernet's frame format on 100-Mbps point-to-point links. A few years later, gigabit Ethernet became available, providing LANs with an upgrade path using the familiar framing format, albeit without a shred of CSMA/CD. By bridging together compatible frames at any speed, Ethernet was able to connect lowly 10-Mbps desktops to fast gigabit servers. And its funda- mental simplicity kept the cost below competing technologies. Ethernet LECs parlayed the "cool" factor of Ethernet with its perceived low cost. Start-ups such as Cogent, Allied Riser, and Yipes took in well over a billion dollars of investor money [16] during the late 1990s boom. Sometimes they were able to acquire fiber from existing CAPs; in other cases they trenched The Great Telecom Meltdown their own. Some companies issued stock, which rose with the boom. This was a tool for expansion in an unusual way: One of the problems the ELECs had was getting landlords' permission to run cable within large office buildings. In order to grease the skids, some ELECs gave landlords stock in exchange for access. From a customer perspective, the ELECs were a good deal. Ethernet, after all, was supposed to be cheaper than "telecom" circuits. And during the boom, profitability was SO far away that the cost of providing service was not a major issue. Cogent was known as a price leader, offering 100-megabit Ethernet con- nections for $1,000 per month. Of course this was not the same as backbone ISP bandwidth: As with DSL, Cogent's average customer's usage was a low per- centage of the peak rate, SO its backbone connections could be heavily oversub- scribed. Cogent was able, in early 2002, to acquire bankrupt backbone ISP assets of PSInet, reducing its dependence on other providers and giving it a long-haul backbone as well as a more diverse product base. But the bubble burst hard for the ELECs too. Allied Riser was in deep financial difficulties when Cogent acquired it in late 2001 in exchange for a small amount of stock and th