Which of the following technologies is a common WAN technology used to connect sites?

• A. MPLS
• B. Bluetooth
• C. USB dial-up
• D. Wi-Fi

Answer: (A)

Connecting sites over a wide area requires a service that can carry diverse traffic with predictable performance across long distances. MPLS—Multi-Protocol Label Switching—does exactly that by using short labels to forward packets through the provider’s backbone. This lets the network support scalable, VPN-like connections between multiple sites, with the ability to prioritize certain traffic (QoS) and efficiently manage paths through the network.

Bluetooth is designed for short-range personal area networks, so it doesn’t scale to inter-site links. Wi-Fi is a local-area wireless technology intended for buildings or campuses, not reliable for long-distance, carrier-grade WAN connections. USB dial-up is an outdated method that isn’t suitable for modern, high-capacity WANs between sites.