1. Routing processor (router CPU) runs the routing algorithm is implemented in [Select] and performs Select functions is executed in the [Select] 2. Router input port - performs a lookup function; implemented in [Select ] Select) is executed in the 3. Router high speed switching fabrics connects the router's input ports to its output ports, implemented in v [ Select] is executed in the 4. Router output ports - transmits these packets on the outgoing link is executed implemented in Select] [ Select ]