What is Cable Internet Access?
When you get a television signal from your cable company, all of the video and audio information for a particular channel takes up a "slice" of bandwidth. It is possible to take one of these channels and use it for Internet access, and none of the other channels will be affected. Not all cable systems are capable of this, however.
Cable companies take a slice of bandwidth and use it to exchange data with your computer. They divide this channel into two subchannels for upstream and downstream data. They expect a lot more downstream data, because most people download a lot more than they upload. In some cases, cable companies can only send data through the cable, but not receive messages from you. If this is the case, you need to use a conventional modem to request information, and cable companies send it to you at high speed through the cable system.
What is DOCSIS™?
Cable modems can be DOCSIS certified or proprietary. DOCSIS stands for Data Over Cable Service Interface Specifications. A DOCSIS certified modem is preferable, as it will work with any DOCSIS compliant cable system. DOCSIS modems are generally easier to support because a lot of documentation is available and many cable companies adhere to the standard. A proprietary modem is less desirable, because it will only work with the system for which it was designed. All USRobotics cable modems are DOCSIS compliant.
Are there limitations of cable Internet access?
There are a few things to be aware of when using a cable modem. There may be over 500 homes in your area using the same "channel" for Internet access. If everyone tries to access the Internet at the same time, your download speeds could slow to a crawl. Your cable company can remedy this by dedicating another channel to Internet access.
Another thing to be aware of is the fact that all cable modem users in your area are on the same network cluster, and may be able to browse others people's computers. You should use always use a firewall, but you especially need to run one when you have a cable modem. A firewall is software that monitors network traffic and prevents unauthorized users from accessing your computer. Firewall software can be downloaded and run on a computer itself, or it can be built into a router. For more about firewalls and routers, read the networking education section.
How do I get Cable Internet Access?
If you already have cable TV, call your cable provider and ask if cable Internet access is available. If your cable provider uses a DOCSIS compliant system, you may be able to purchase your own cable modem and get a reduced monthly rate.