Chapter 17. Using a Cable Modem

Some of the Main Topics in this Chapter are

How Cable Modems Work 270

How Cable Modems Differ from xDSL Broadband Access 273

The Data Over Cable Service Interface Specification (DOCSIS) 274

Choosing Between Cable and DSL 275

The two most popular methods for connecting home users and many small businesses to the Internet are DSL and cable modems. Both have their advantages as well as disadvantages. The preceding chapter explained how DSL works, and in this chapter you will learn about how cable modems work, as well as how they differ in many respects from DSL.

Although a cable modem connection might work for a home user or a small business, you must again think of the service provider before committing your network's connectivity to the Internet. Some cable companies are just great, providing quick resolution to problems, and others are not so great. Again, if you're not getting a good response from your cable company at home, you might want to consider other options before using the same company as a link for your small business.

Note

Depending on where you live, you might not be able to get Internet access using a cable modem. Not all cable companies have the equipment necessary to provide this service, or they are not equipped to extend past their limitations since most cable providers offer "shared" network services. In that case you should consider using xDSL for a high-speed connection to the Internet. Or you may live in a metropolitan area that offers both services. If that is the case, I suggest you read this chapter and Chapter 16, "Digital Subscriber Lines (DSL) Technology," and make your decision based on the topics covered. If you live in an area where neither service is available, you are out of luck, because "two tin cans and a string" uses amplitude modulation instead of digital signaling. Just seeing whether you're paying attention!

Another factor you might think about is the actual cost for cable modem services. Because many cable companies are now trying to maximize their revenues, since the cable TV market is pretty much saturated, you might find that you can get a special deal when subscribing to both cable TV and Internet access. If anything, you may be able to get a few months of cable-modem access at a reduced price.