Speed
The most common question we get in DSL vs Cable Modem discussions is which service is faster? Cable download speeds are up to 2 times faster than 1.5Mbps DSL about 50x the average speed of a 28.8K Modem.DSL Speed
DSL services typically offered today typically range in performance from 128 kbps to 1.544 Mbps. It can be difficult to pin down precise speed numbers for DSL because of the many variations in equipment. DSL is also a distance-sensitive technology, and that complicates the performance picture even further. The bandwidth available to a home user, for example, depends significantly on the length of cabling running from the home to the provider's facilities as well as the electrical quality of that line.
Although it may seem limiting, asymmetric DSL services are still more commonly used than symmetric ones. Most Net users require more bandwidth for surfing the Web (that involves frequent loading of Web pages) than they do for sending email or Web publishing (that involves transmitting data to remote locations). Therefore, an ADSL user tends to spend very little of their time limited by a 128 kbps upstream data rate. Symmetric DSL (SDSL) service can be more appealing to business customers, however, who tend to use a different mix of applications and need more bandwidth in both directions.
Cable Modem Speed
Cable Modem service providers usually don't quote absolute performance numbers like the DSL vendors because of the differences in dedicated versus shared bandwidth. Actual speeds will vary. Many factors affect download speeds.
Today, cable modem retains a performance advantage over DSL. Most cable networks have not yet reached high enough subscriber levels to make the shared bandwidth issue critical.
DSL vs Cable Modem Cost / Pricing
In the past year, DSL has lowered their prices to the same level as cable. No matter what the service, DSL and Cable services both offer a fair amount of email addresses, junk and spam filtering, and a firewall of some type. Both services are rich with features, and prices are low enough for both services to take advantages of specials and deals
Is the cable company in your neighborhood offering a better deal than cable modem service? Some people live in places where neither cable modem nor DSL service is available, but many others have the choice of both.
Security
When comparing cable modem vs DSL service, network security might be the most controversial item on the comparison chart. At first glance it appears one clearly wins the security battle over the other, but does this commonly-held opinion stand up to closer scrutiny?
Cable Modem Security
Most cable providers avoid security problems by bundling security features in the cable modem hardware. In particular, basic network firewall capabilities will prevent files from being viewed or downloaded. Most cable modems today also implement the Data Over Cable Service Interface Specification (DOCSIS). DOCSIS includes support for cable network security features including authentication and packet filtering [3].
DSL uses dedicated rather than shared cabling, and DSL customers in a given neighborhood do not appear as nodes on a LAN. From this, many have concluded DSL service provides better security. However, this argument is at best an oversimplified one.
Considerations for Both DSL and Cable
Both DSL and cable provide always-on connection capability. By design, DSL and cable customers can stay logged into the Net indefinitely if they choose. This feature provides great convenience but also creates a security risk. First, the "law of averages" means simply being online longer increases the likelihood of attack proportionately. But more importantly, the always-on feature typically means the customer will be using the same network address -- a static IP address -- for the duration of their online session.
How do attackers actually penetrate a home or small office network? In general, they exploit weaknesses in applications or in the underlying operating system. Typically vulnerable applications include email, databases, and instant messaging and conferencing tools. Operating systems contain many potentially vulnerable network services like FTP that utilize specific network ports.
Many DSL and cable modem customers choose to purchase routers to protect their internal systems. A DSL or cable router enhances the functionality of the basic modem with security features such as packet filtering and network address translation (NAT). One can usually build an equivalent security system with the basic modem and proxy software installed on the computer directly connected to the modem. Broadband routers simply provide a convenient and operating system-independent packaging of security features.
Conclusion
There really isn't a clear winner when you compare DSL vs Cable Modem. First you should find out which is available in your area. If you have a choice between DSL vs Cable Modem then take a look at our guideline and make the choice based on what is most important to you : speed, price, security, etc.