:: Comparison between DSL and cable modem

Compared to the traditional dial-up access, both DSL and cable modems offer high speed internet access, which opens up a whole new world of possibilities for network connectivity and applications for home and small business users.

Theoretically speaking, the speed of cable modems (max 30Mbps) is more than DSL (Max 10Mbps). In practice, though, the speed advantage of cable over DSL is much lower than might be apparent at first. Both cable modem and DSL performance vary from one minute to the next depending on the pattern of use and traffic congestion on the Internet.

Cable modem uses shared bandwidth, whereas DSL has dedicated local bandwidth. The speed of the cable modem depends on the number of subscribers in the neighborhood, who are currently active, so cable modem will perform relatively slower during peak usage time.

Today, the cable modem retains a slight performance advantage over DSL but this advantage seems to be a short-term one. Most cable networks have not yet reached high enough subscriber levels to make the shared bandwidth issue critical.

Both cable and DSL service providers have commonly employed the controversial practice of bandwidth caps for their home customers. Bandwidth caps place an artificial limit on the maximum speed a customer can achieve, as the system configuration monitors and controls the current usage.

DSL is a distance sensitive technology. The bandwidth available to a home-user depends on the length of the cabling running from the home to the provider’s facilities and its quality. DSL normally only works within a certain distance (typically 16000 feet) of the telephone company central office so it is unusable for many rural and semi-rural customers.

Asymmetric DSL services are still more common than the symmetric ones especially for home users who need different speeds for different applications such as data loading or emailing. Symmetric DSL is more used by business customers.

Security is very low in cable modems as compared to DSL due to shared bandwidth. Your programs can be easily hacked by any people using the same cable, whereas in DSL due to dedicated line, security is greater. Also when evaluating cable modem service providers, consider the technology they offer. Does their modem implement DOCSIS, for example, and if so, what security options have been enabled? Does the provider offer dynamic IP assignment, and does one's IP address change at a periodic interval, or only when one first goes online?

DSL equipment and recurring costs are higher than cable modems. In cable modems a coaxial cable traveling in a neighborhood from house to house can provide high-speed service to thousands of customers. A single piece of equipment at the cable company’s office can patch those thousands of customers onto the Internet. DSL on the other hand requires a separate pair of wires for each subscriber, so the costs increase. The phone company needs to install a special DSL modem for each phone line at its central office.

There are 3 parties involved in a DSL operation, The DSL provider, the Internet service provider and the telephone company. So if anything goes wrong, fingers are pointed at each other.