Certified Information Systems Security Professional (CISSP) Practice Exam

What does Digital Subscriber Line (DSL) utilize to provide service?

1. Fiber optic cables

2. Satellite connections

3. Coaxial cables

4. Existing copper pairs

The correct answer is: Existing copper pairs

Digital Subscriber Line (DSL) technology utilizes existing copper pairs to provide internet service to users. The method relies on the traditional telephone lines that are already in place, allowing for easy and cost-effective deployment of broadband services without the need for extensive infrastructure changes. DSL works by transmitting data over the high-frequency range of the copper wires, which is distinct from the frequency used for voice services. This enables simultaneous voice and data transmission without interference. Since many areas already have the necessary copper infrastructure, this makes DSL an accessible option for many users, particularly in urban and suburban environments. In contrast to other options, fiber optic cables offer significantly higher speeds but require new installations, while coaxial cables are used by cable internet services rather than DSL. Satellite connections can provide internet access without ground-based infrastructure but often come with higher latency and are not associated with DSL technology at all.