Labeling Packets in an MPLS Network

Answer - D.

A Forwarding Equivalence Class (FEC) is a term used in Multiprotocol Label Switching (MPLS) to describe a set of packets with similar and / or identical characteristics which may be forwarded the same way; that is, they may be bound to the same MPLS label.

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The correct answer is D. FEC (Forwarding Equivalence Class).

MPLS (Multiprotocol Label Switching) is a protocol used to improve network performance and scalability by directing data packets through a series of predetermined paths, called label-switched paths (LSPs), rather than individually routing each packet based on its network address.

FEC (Forwarding Equivalence Class) is a term used in MPLS networks to refer to a group of packets that are treated the same way as they traverse the network. Each FEC is assigned a unique label, which is added to the packet as it enters the MPLS network. This label is used by the routers in the network to determine the path the packet should take to reach its destination.

To illustrate this process, imagine that a router receives a packet with a destination IP address. The router would then determine the FEC associated with that address and attach the corresponding label to the packet. This label would then be used to forward the packet through the MPLS network along the predetermined LSP.

In summary, FEC is the label applied to packets in an MPLS network to indicate which forwarding equivalence class they belong to, allowing routers to forward them along the appropriate label-switched path.