TAILIEUCHUNG - Suse Linux 9.3 For Dummies- P10

Suse Linux For Dummies- P10:This part is all about getting you started on your way to a lasting relationship with SUSE Linux. Before you can begin your SUSE Linux experience, I spend a chapter explaining what SUSE Linux is and what you can do with SUSE Linux (pretty much anything you can do with a PC that runs Windows). | _Chapter 7 I Want My Internet Now 115 Cable company To Internet backbone Cable Modem Termination System CMTS A neighborhood one or more homes with cable modems Figure 7-4 Cable modems provide high-speed Internet access over the cable TV network. The coaxial cable that carries all those hundreds of cable TV channels to your home is a very capable signal carrier. In particular the coaxial cable can carry signals covering a huge range of frequencies hundreds of megahertz MHz . Each TV channel requires 6 MHz and the coaxial cable can carry hundreds of such channels. The cable modem places the upstream data in a small frequency band and expects to receive the downstream data in a whole other frequency band. Please purchase PDF Split-Merge on to remove this watermark. 116 Part II Test Driving SUSE__ At the other end of your cable connection to the Internet is the Cable Modem Termination System CMTS also known as the head end that your cable company installs at its central facility. Refer to Figure 7-4. The CMTS connects the cable TV network to the Internet. It also extracts the upstream digital data sent by your cable modem and by those of your neighbors as well and sends all of it to the Internet. The CMTS also puts digital data into the upstream channels so that your cable modem can extract that data and provide it to your PC via the Ethernet card. Cable modems can receive downstream data at the rate of about 30 Mbps and send data upstream at around 3 Mbps. However all the cable modems in a neighborhood share the same downstream capacity. Each cable modem filters out separates the data it needs from the stream of data that the CMTS sends out. Cable modems follow a modem standard called DOCSIS which stands for Data Over Cable Service Interface Specification. You can buy any DOCSIS-compliant modem and use it with your cable Internet service all you