In the world of connectivity, two terms pop up a lot — DSL and fiber-optic. Laid out side by side, consumers and organizations see many similarities in service options, but the technology that supports each is very different.

For any business looking to find the most cost-efficient and trustworthy data connection, it’s important to understand each format along with its limitations and extraordinary features. DSL vs fiber-optic: how do they compare?
What is DSL?
The digital subscriber line (DSL) has its roots back in the days of Ma Bell and old-school copper telephone connections. Phone lines have a reputation of being limited and the earlier technology used to support them would not be sufficient for today’s challenges. The 1980s saw a change in the usefulness of the telephone line as broadband took over and digital became king.
Today, DSL provides a high-speed connection using the same telephone wires that at one time were exclusively for voice communication. Analog connections purposely limited frequencies to cut down on interference during phone calls. The advent of digital communication made it possible to use much more of the phone line’s capacity to transmit data.
DSL also works by creating download speeds that are faster than uploads because that is what most users need. It is based on the premise that businesses and consumers download more than they upload.
Pros and Cons of DSL
The advantages of DSL include:
- DSL uses existing phone lines, so it doesn’t require additional wiring
- The internet stays open, so it’s possible to have a landline and internet connection at the same time, unlike dial-up service that also used phone lines
- DSL comes with high-speed connections that work through a standard modem
- DSL is easier to find because it uses copper lines that have been spread throughout the county for decades
The cons:
- DSL has some distance limitations
- Uploads can be slow at times
What is Fiber-Optic?
Fiber-optic cables also have a connection to telecommunication. Unlike traditional phone lines, fiber-optics carry sound piggybacked on light signals via optical fibers, essentially thin glass strands wrapped in plastic. The design of fiber-optic allows cables to carry sound, electrical signals and data long distances and even around turns. Each fiber-optic cable is made up of:
- Pure glass pulled into strands as thin as hair
- Two layers of plastic around the glass strand
The combination of the glass and plastic wrapping creates a mirror that is able to reflect light. At the end of each cable is a laser that blinks on and off to send light down the fiber-optic cord to a photodetector. The photodetector picks up the light which is converted into a digital signal.
The Pros and Cons of Fiber Optic
The most obvious benefits of fiber-optic communication are speed and distance. The downside is many areas are not set up with fiber-optic cable.
DSL vs Fiber-Optic
These are two very different forms of technology. Of the two, fiber-optic offers the most benefit but it is the hardest to find. DSL, on the other hand, is more readily available but not as good a resource for communication. Other critical distinctions include:
- DSL works through copper phone lines, fiber-optic via fiber-optic cables
- DSL is available in approximately 90 percent of the U.S. Fiber-optic internet only reaches about 25 percent, but that will eventually change over time as more cable is installed.
- DSL speed will vary based on the distance to the service provider. Fiber-optic is not limited by distance, so the speed is more consistent.
Both communication formats work, but DSL tends to be utilized more in rural areas. FIber-optic provides the best service because the technology is more sophisticated, but it is harder to find. Check here for fiber optic availability near your business or commercial location.
PS LIGHTWAVE provides high-speed, fiber internet for public and private commercial entities in the Greater Houston and surrounding areas.
Through our high-quality infrastructure, innovative technology and expert, locally based support, we deliver not only the best in connectivity and reliability but in scalability and redundancy. We invite you to learn more about our services, our history and our dedicated team.