ADSL
Description: Asymmetric Digital Subscriber Line provides an Internetconnection using an existing telephone line, but the line remains free fornormal phone calls. It is called "asymmetric" because it receives data muchfaster than it can send it.
Speed: 128 kilobits/sec to 10 megabits/sec
Pros: Fast speed, always on, shared voice and data on the same line
Cons: Availability limited by the distance from the local phone switch
Verdict: Good for field offices and telecommuting
SDSL
Description: Symmetric Digital Subscriber Line provides an Internet connectionusing an existing telephone line, while leaving the line available fornormal phone calls. It is called "symmetric" because it sends and receivesdata at the same speed.
Speed: 144 kilobits/sec to 1.5 megabits/sec
Pros: Fast speed, always on, sends data as quickly as it receives it,business-grade support
Cons: Business-grade pricing
Verdict: Good for offices that send and receive large volumes of dataand that require top-grade service
RADSL
Description: Rate Adaptive Digital Subscriber Line lets agencies useexisting phone lines to connect local-area networks to a central network.This is a do-it-yourself technology, not an Internet access service.
Speed: 1.5 megabits/sec to 2.1 megabits/sec
Pros: Fast speed, always on, affordable in-house service for largenetworks
Cons: Not available as a service
Verdict: Perfect for federal agencies with large, spread-out installations
Cable Modem
Description: Cable modem provides an Internet connection using existingcoaxial cable television lines. Customers share the neighborhood line likea telephone party line, so speed and performance are affected by the numberof users who are online.
Speed: Up to 38 megabits/sec
Pros: Fast speed, always on, doesn't use a phone line
Cons: Possible performance and security concerns because of sharedbandwidth, availability limited to mostly residential areas.
Verdict: Great for telecommuters, not as good for small offices becausethe service might not be available in non-residential areas