1.7 Router Architecture

A router provides several important functions in order to ensure proper packet forwarding, and to do so in an efficient manner.

A router is a specialized computer that handles three primary functions:

	Packet Forwarding: On receiving an incoming packet, a router checks whether the packet is error free. After inspecting the header of a packet for destination address, it performs a table lookup function to determine how to find the appropriate outgoing link.
	Routing Protocol Message Processing: A router also needs to handle routing protocol packets and determine if any changes are needed in the routing table by invoking a routing algorithm, when and if needed.
	Specialized Services: In addition, a router is required to handle specialized services that can aid in monitoring and managing a network.

1.7 Router Architecture

Figure 1.4: Router architecture: a functional view

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture

1.7 Router Architecture