Traditional IP packet forwarding analyzes the（71）IP address contained in then network layee header of each packet as the packet rravels from its sourse to its final destination. A router analyzes the destination IP address independently at each hop in the network. Dynamic（72)protocols or staitic configuration builds the database needed to analyze the destination IP address(the routing table). The process of implementing traditional IP routing also is called hop-by-hop destination-based (73) routing. Although successful,and obviously widely deployed,certain restrictions,which have been realized for some time,exist for this method of packet forwarding that diminish its（74）.New techniques are therefore required to address and expand the functionality of an IP-based network infrastructure. This first chapter concertrates on idenfifying these restrictions.and presents a new architecture,known as multiprotocl（75）switching,that provides solutions to some of this restrictions.
