Chapter 5 TCP/IP: Routing – Part 1TCP/IP – Part 4 - RoutingTCP/IP-Part 4a: RoutingDifferent Types of Routing Centralized and Decentralized RoutingDifferent types of Routing Decentralized Routing: Static RoutingDifferent types of Routing Decentralized Routing: Dynamic (Adaptive) RoutingDifferent types of Routing Decentralized Routing – Dynamic (Adaptive) Routing Distance Vector Dynamic RoutingDifferent types of Routing Decentralized Routing – Dynamic (Adaptive) Routing Link State Dynamic RoutingDisadvantages of Dynamic RoutingDifferent Types of Routing Connectionless and Connection-Oriented RoutingDifferent Types of Routing Quality of Service (QoS) RoutingChapter 5 TCP/IP: Routing – Part 1Dr. V.T. RajaOregon State UniversityTCP/IP – Part 4 - RoutingOutlinePart 4a:IntroductionDifferent Types of RoutingPart 4b:Routing ProtocolsRouting TablesTCP/IP-Part 4a: RoutingRouting: Path taken by message from sender to final destinationRouting Table: Devices that perform routing have a routing table that specifies route to different destinations.The routing tables are constructed/updated using different types of routing technique(s). Different Types of Routing–Centralized–Decentralized •Static •Dynamic Routing (Distance Vector and Link State Dynamic Routing)– Connectionless and Connection-Oriented Routing– QoS RoutingDifferent Types of Routing Centralized and Decentralized RoutingCentralized and Decentralized RoutingCentralized Routing–All routing decisions are made by one central computer–Example: Decentralized Routing–Computers/routers in network make their own routing decisions following a formal routing protocol, which could be capable of self-adjusting, and adapting to changes in the network configurationsDifferent types of RoutingDecentralized Routing: Static RoutingStatic RoutingStatic–Routing table is developed by the network manager–Changes are made to the routing table only when computers are added or removed from network–Example:Different types of RoutingDecentralized Routing: Dynamic (Adaptive) RoutingDynamic (Adaptive) RoutingDynamic Routing–Used when there are multiple routes and it is important to select the best (or fastest) route, in order to route messages away from traffic on busy circuits–An initial routing table is developed by the network manager, but is continuously updated by the computers themselves (with the help of routing protocols) to reflect changing network conditions, such as network trafficDifferent types of RoutingDecentralized Routing – Dynamic (Adaptive) RoutingDistance Vector Dynamic RoutingDistance Vector Dynamic RoutingDistance Vector Dynamic Routing–Routing decisions are made based on # of hops along a route–What is a hop?•Examples: –A - C (via B): »# of hops = –A – C (via D, E & F):»# of hops = –Computers periodically (could be as often as every 1-2 minutes) exchange information on the hop count and sometimes the relative speed of the circuits in route with their neighborDifferent types of RoutingDecentralized Routing – Dynamic (Adaptive) RoutingLink State Dynamic RoutingLink State Dynamic RoutingLink State Dynamic Routing–Routing decisions are based on several factors:•Number of hops in each route•Speed of circuits in each route•Traffic conditions on each route (How busy the route is?)•Reliability of each routeDisadvantages of Dynamic RoutingRequires more processing effort from each computer on the network compared to centralized or static routing“Compromises” on network capacity during transmission of route status informationDifferent Types of Routing Connectionless and Connection-Oriented RoutingConnectionless and Connection-Oriented RoutingA message may be segmented into several packetsConnectionless Routing–Different packets of the same message could take different routesConnection-Oriented Routing–A virtual circuit (VC) is set up between sender and receiver–A VC is one that appears to be a point-to-point circuit–All packets follow the same VC route;–Overhead involved in establishing and closing VC before and after transmission of all packetsDifferent Types of Routing Quality of Service (QoS) RoutingQuality of Service (QoS) RoutingQuality of Service (QoS) Routing–Special type of connection-oriented dynamic routing protocol–Different messages or packets are assigned different priorities•Applications: –Different classes of service are defined for different