Download Speed: 56kbps, 128kbps or 256kbps
Upload Speed: 56kbps, 128kbps or 256kbps
Pros: Faster than dial-up, guaranteed speed, same upload and download speeds
Cons: No unlimited access - expensive, slower than other broadband service, outdated technology

ISDN was created in the early days of dial-up when connections were even slower than they are today. ISDN connections are essentially direct phone line connections to the phone company to provide consistent speed. The standard speed is 56K, but lines can be combined to form faster connections. This was an advantage for those that couldn't afford a T1 or faster connection, but wanted something with more muscle than dial-up. The major advantage of ISDN is the speed almost never changes. 56K ISDN is always 56K ISDN (or within a few Kilobits). The biggest disadvantage of ISDN is cost. In addition to monthly fees, there are usage charges, as well. This was not as important when dial-up service also had usage charges, but with most other home services offering unlimited access, ISDN is no longer viable. Cable and DSL services (described below) offer greater maximum speed and usually a lower total cost. Most ISDN is used for radio remote broadcasts rather than individual users.

Download Speed: Several flavors up to 1.5Mbps, 3Mbps or more, depending on service
Upload Speed: up to 512kbps, depending on service
Pros: Fast speed, more consistent than cable modems, leaves phone line free to make calls, can be faster than cable during peak usage times
Cons: Costs 2-3 times as much as dial-up, usually slightly slower than cable during non-peak times, often requires user to purchase equipment

DSL (or Digital Subscriber Line) is the latest offering from the phone company, as well as some other independent providers. DSL comes in two flavors: ADSL and SDSL. ADSL (or Asymmetrical Digital Subscriber Line) is the most common type of DSL service. This usually has a fast download speed, with a much slower upload speed. This is okay because most of the information is received by the user rather than sent. Most of the uploaded information is limited to requests for a web page or sending an e-mail message. These communications generally don't require as much bandwidth as downloading web pages, photos or multimedia files. Of course, the upload speed is still 3 or 4 times faster than dial-up. SDSL has an upload speed that is closer to its download speed. Unfortunately, the faster the upload speed, the slower the download speed. DSL uses your existing phone lines to provide an Internet connection. Unlike dial-up, though, the connection is "always on." There is no dialing a phone number or waiting to log on. Just open your WEB BROWSER and you're on the 'net (some providers do require you to enter a user name and password). DSL doesn't tie up your phone line, either. Voice and data information can travel through the same line without interfering with each other so you can surf and talk at the same time. One problem with DSL is its limited service area. If you don't live within a few miles of your local provider, you probably can't get service. This is improving, though, as providers add repeaters to increase range.

Cable Modems: