Traditional IP packet forwarding analyzes the （ 1）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 （ 2） 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 （ 3）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 （ 4）.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 multiprotocol（ 5）switching,that provides solutions to some of this restrictions.

( 1).A.datagram 
B.destination
C.connection
D.service
( 2).A.routing
B.forwarding 
C.transmission
D.managerment
( 3).A.anycast
B.multicast
C.broadcast 
D.unicast
( 4).A.reliability
B.flexibility
C.stability 
D.capability
( 5).A.cost 
B.cast 
C.mark 
D.label