N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 6 - Internet, Intranet, Extranet, e-Commerce and Web Services                                      Slide 20 of 70 _________________                                                                                  __________

                                                 Access to an ISP

                                                    Dial-up

                                                    Cable Modem

                                                    xDSL

                                                    Satellite

_________________                                                                                  __________

Many options are available to customers to access an ISP. More and more customers are opting out in favor of high speed connections. Many who have dial-up access are migrating to xDSL or Cable Modem connections.

Dial-up - Supports up to 56 K bps access to the Internet. This service is offered by the telephone companies.

Cable Modem - This type of access supports 1.5 M bps over a cable company's cable. A cable modem is used to connect the user's PC to a local cable TV line. The cable modem attaches to a standard 10BASE-T Ethernet card in the computer. A cable modem can be integrated or added to a set top box that provides TV channels for Internet access. Cable modems are furnished as part of the cable access service. Cable companies initially gave a cable modem free but now they give the option to Internet subscribers to pay a monthly charge or buy outright.

xDSL - Digital Subscriber Line is a technology that provides high bandwidth to homes and businesses over regular telephone lines. xDSL refers to different variations of DSL such as Asymmetric Digital Subscriber Line (ADSL), High bit-rate Digital Subscriber Line (HDSL),  Rate Adaptive Digital Subscriber Line (RADSL), and Very High Data Rate Digital Subscriber Line (VDSL). A DSL line can support data rates at 6.1 M bps to customers who are close to a telephone company central office. A DSL line will support continuous transmission of motion video, audio, and even 3-D effects. Most customers subscribe to an ADSL line which supports 6.1 M bps downstream and 620 K bps upstream.

Satellite - A satellite Internet connection is available in the North American marketplace from companies like DIRECWAY (http://www.mini-dish.com).