To some extent, DSL cables have a similar structure as Ethernet cables: both of them are constructed of copper cables to transfer data using electrical impulse. The difference is that DSL uses the standard phone plug while typical Ethernet cables have two extra pairs of twisted copper wires with a larger plug as shown in the figure below. As for the fiber optic cable, the structure is evidently distinct. Optical cable consists of fiber core wire, outer jacket and strengthening members, and it delivers data using fiber instead.
Speed is a key point for choosing the best cable for the Internet. Historically, DSL speeds are slow and it is difficult to specify the exact speed. How fast the DSL is often depends on your DSL internet provider and the technology used, generally less than 1 Mbps, but still some up to 100 Mbps.
Ethernet speed has been limited to 10 Mbps once a while, however, the development of Fast Gigabit offers rates of up to 100 Mbps and now Gigabit Ethernet is getting popular, delivering data at a higher rate. For home use, in general, Ethernet cable download speed usually starts from 10Mbps to 500Mbps, and the upload speed is from 5Mbps to 50Mbps.
Fiber optic cable speed is the fastest among these three internet access technologies. The download and upload speed of a fiber patch cord can be anywhere from 250Mbps to 1000Mbps and not affected by the distance from ISP. Fiber optic cables usually contain many strands, and a single strand of fiber optic cable has been proven to be able to carry data at up to an extremely fast 100Tbps, which suggests the superior speed of fiber optic cables.
DSL provides customers with a dedicated line, therefore it is less likely to cause Internet security issues. The information passes between the central office and the customers’ home without passing through connection to other customers’ modem.
Ethernet cables using electrical signals are vulnerable to electromagnetic interference and easy to get intercepted by hackers at the hardware level.
The light transmission in fiber optic cables is not susceptible to EMI and RFI as the copper connections do and any physical break in the system is easy to identify, thus there is no way for hackers to listen in on the transmission. Overall, fiber optic cables are the most secure ones with high security and low privacy risk.
The cost of DSL, Ethernet or fiber cable varies depending on your specific need, your location, your provider, the terms of the agreement and other elements. When you are about to install one of them for internet access, you should take not only the cable cost into account but also the installation and activation fees.
Typically, the fiber optic internet cost is the most expensive one because the fiber installation is more complicated than coax with many variables to be considered and you need to pay for the devices matched with fiber optic cables, professional installers, etc. Since the Ethernet cable infrastructure is more expensive than the telephone, ethernet cable installation costs more compared with DSL.