Users who regularly access the Internet will appreciate cable Internet service for two reasons: It’s fast, and it’s always available. The aging dial-up Internet service is only available when you dial into your Internet service provider’s server via your dial-up modem. And whereas the dial-up Internet service transfers data at a mere 56Kbps (kilobits per second), a cable modem can transfer data at up to (theoretically) 30Mbps (megabits per second). That said, your cable Internet service will never offer the maximum speeds. Cable speed will slow somewhat as more people in your neighborhood access the Internet over cable. Also, some Internet service providers cap your access at a certain speed and charge more for faster service. Maximum cable Internet speeds of about 5Mbps or even lower are common but are still much faster than dial-up. DSL is generally a little slower than cable but in some cases lets users upload data to the Internet at a faster pace.

Cable service prices vary by ISP and location, but many users will find that the basic (slowest) service option is available for $40 to $60 per month.

Anatomy Of A Cable Modem

As with a dial-up or DSL modem, the cable modem is the device that shuffles data between your computer and the cable that leads to your ISP. Cable modems come in various shapes and sizes; many are just a little larger than a paperback book. Some cable modems have only two ports: the coaxial port that accepts your home’s coaxial cable and an Ethernet port. The Ethernet port is also known as an RJ-45 port and resembles a large phone jack. (Phone jacks are also known as RJ-11s.) The device connects to your computer (or to a router, which connects to your computer) via an Ethernet cable, which means your computer must also have an Ethernet port. The Ethernet port is a standard feature on most computers; look for it at the back of your desktop system or on the side of your notebook computer. Some new cable modems also have USB (Universal Serial Bus) ports that let you connect your computer or other devices via a USB cable.

Cable Internet service generally supports two-way modems, which download and upload data to and from the Internet. You may run across a one-way modem, which can only download data over the cable service. If this is the case, your computer will also need a dial-up modem in order to send data to the Internet.

Some cable modems also have a small reset button (generally at the back of the device, by the ports). The reset button restarts the modem so that it restarts its standard self-test and connection scanning procedures. If the modem doesn’t have a reset button, you’ll need to reset it by unplugging the power cable for 10 seconds to a minute. (In our experience, you’re better off waiting a full minute.) You can use this feature to fix certain modem errors. You may also need to reset your modem to take advantage of higher network speeds when your ISP raises the speed cap.

Buying Tips

In most cases, you can sign up for a service and get connected in a matter of days. Keep these tips in mind as you shop for a high-speed service.

Shop around. Check with your cable TV company to find out if it is the only local cable ISP. In many cases, other cable ISPs offer their services over the same cable. You may find better deals by subscribing to one of these lesser-known services.

Look for the ISP first. Don’t buy a cable modem before you select a service—some providers loan you a cable modem as part of the service, and some may require you to use their own modems.

Share your connection. Most service providers let customers put several of their own computers on a connection (generally via a router), but some don’t. Visit your service provider’s Web site or ask the technician when she installs the cable modem.

Troubleshooting

Your cable modem probably won’t cause as many network headaches as your computer and router, but don’t overlook it when you’re searching for the cause of an Internet connection failure. You won’t be able to look up the service provider’s phone number online if Internet connectivity stops, so have the number (or the yellow pages) handy.

Start by resetting your modem. If you have a router, reset it, too. If you still don’t have a network connection, you’ll want to call your ISP. Don’t assume that the network is functioning simply because your TV set is on because server problems and other mishaps can interrupt network service without disturbing TV.

If you run across an Invalid DHCP (Dynamic Host Configuration Protocol) Lease error message, you’ll need to change the way your cable modem updates its IP (Internet Protocol) address (the unique address that identifies it to the network). This problem occurs because Windows sometimes assigns an IP address to your cable modem before it has a chance to get one from your ISP’s server.

According to Microsoft, you can solve this problem for a one-way cable modem by using the Ipconfig menu. Click the Start button and then click Run. When the Run window appears, enter cmd into the Open field. Click OK. When the CMD.EXE window appears, enter ipconfig and then press the ENTER key. A Windows IP Configuration message will appear. It lists several addresses, including the Ethernet port that connects your computer to the cable modem (probably called Ethernet Adapter here).

Check the IP address line. If the address numbers start with 169.254, Windows’ APIPA (Automatic Private IP Addressing) feature is the culprit. To let the cable modem find the appropriate IP address, enter ipconfig/release and then press the ENTER key. You’ll find that the IP Address changes to 0.0.0.0. Next, type ipconfig/renew and then press the ENTER key. Close the CMD.EXE window. Now your modem will have the correct IP address.

If you have a two-way modem or want more information about the problem, please visit Smart Computing's Tech Support Center (www.smartcomputing.com/techsupport), click Search By Error Message Text, and then enter Invalid DHCP Lease.

Get Connected

Cable modems attract a variety of Internet users. Gamers love cable modems, as the high speeds let them play graphics-intensive games online with other people. Music enthusiasts enjoy downloading songs from music services at much faster speeds than dial-up can provide. And many people like cable service simply because it doesn’t tie up the phone line.

by Joshua Gulick