Which technology uses labels attached to packets to determine forwarding paths through a network?

• A. Multiprotocol Label Switching
• B. Virtual Local Area Network
• C. Open Shortest Path First
• D. Border Gateway Protocol

Answer: (A)

Multiprotocol Label Switching uses labels attached to packets to decide where they should be forwarded next. At the edge of the network, a label is affixed to each incoming packet, and the core routers switch based on that label rather than performing a full IP lookup at every hop. As the packet traverses the network, the label may be swapped or removed, guiding it along a precomputed path. This approach speeds forwarding, enables precise traffic engineering, and supports VPN services by keeping forwarding decisions simple and predictable.

The other options don’t rely on per-packet labels to drive path decisions: a VLAN Segments a broadcast domain within a LAN, not a global path for packets across a network; Open Shortest Path First determines routes by building a topology and computing shortest paths, not by labeling packets; Border Gateway Protocol handles interdomain routing between autonomous systems, again without per-packet label-based forwarding.