re are no busy signals and tied up telephone lines like there are with dial-up modems. Another advantage of cable modem technology is that it has tremendous upgrade capacity. Twisted pair telephone lines have already used up a sizeable portion of their inherent bandwidth capacity (Halfhill, 1996). On the other hand, MSOs have already created a tremendous amount of shared bandwidth with their upgrades to HFC networks. Furthermore, as the number of cable modem users grows, and too many users try to share the available bandwidth, the cable operators have the capability to add more. Many MSOs have six optical fibers in their cable bundles and are only currently using two of them. The MSOs could light up these unused fibers and greatly increase the amount of bandwidth to be shared. Another option is to allocate additional 6 MHz channels for high-speed data. Still, another option for adding bandwidth is to subdivide the physical cable network by running fiber-optic lines deeper into neighborhoods. This reduces the number of cable modems served by each node segment, and thus, increases the amount of bandwidth available to subscribers (Medin, 1999). Another advantage of cable modems is that they are not the traffic bottlenecks on a cable data network. The cable modems have tremendous throughput capacity. It is the other components of the cable network and the Internet itself that slow traffic down. Some of the items that slow down a cable data network are the 1.5 Mbps T-1 cable Internet connection, the Ethernet PC interface card, current PC technology, and plain old Internet congestion. But all these items are being upgraded to allow ultra-fast data traffic. The Internet is going through growing pains and there is still a lot of growing to do (Medin, 1999). Cable modem technology does have some disadvantages. Cable data networks are still in their infancy and are going to experience some growing pains as the rest of the In...
