ion. In fact, it is not uncommon to encounter networks that have more management traffic traversing their circuits than actual user traf- fic. What's wrong with this picture? Distance vector works well in small networks where the number of multihop traverses is relatively low, thus minimizing the impact of its bandwidth-intensive nature. Distance vector protocols have that name because of the way they work. Recovering physicists will remember that a vector is a measure of something that has both direction and magnitude associated with it. The name is appropriate in this case, because the routing protocol optimizes on a direction (port number) and a magnitude (hop count). Since networks are growing larger, traffic routinely encounters route solutions with large hop counts. This reduces the effectiveness of dis- tance vector solutions. A better solution is the link state protocol. Instead of transmitting entire routing tables on a scheduled basis, link state pro- tocols use a technique called flooding to only transmit changes that occur to adjacent devices as they occur. This results in less congestion and more efficient use of network resources and reduces the impact of multiple hops in large scale networks. Both distance vector and link state protocols are in widespread use today. The most common distance vector protocols are the Routing Infor- mation Protocol (RIP), and Cisco's Interior Gateway Routing Protocol (IGRP) and Border Gateway Protocol (BGP). Link state protocols include Open Shortest Path First (OSPF), commonly used on the Internet, as well as the Netware Link Services Protocol (NLSP), used to route IPX traffic. Clearly, both connection-oriented and connectionless transport techniques, as well as their related routing protocols, have a place in the modern telecommunications arena. As QoS becomes such a critical com- ponent of the service offered by network providers, the importance of both routing and congestion control becomes apparent. We now turn our attention to the second area of responsibility a