Router with Fast Convergence: LSA Correlation
- Technology Application
- Routers play an essential role in the operation of Internet. Internet-related devices are constantly on the rise with close to 1.7 billion Internet users worldwide. These numbers represent a 380% increase in growth in the past decade. The global router market is projected to reach $15.9 billion by 2015. In 2008, North America dominated the revenues in the global market for service provider and enterprise routers followed by Europe and Asia-Pacific. As the number of Internet users and Internet-enabled applications continues to increase, it is now critical to achieve quick convergence to changes in the network topology without overloading routers. LSA correlation technology will be of great advantage to wide area networks that use OSPF and IS-IS protocols. Both Enterprise and Internet Service Provider routing systems can benefit greatly from this novel method of fast convergence.
- Detailed Technology Description
- Dr. Mukul Goyal has devised a new method, called LSA Correlation, to achieve fast convergence to the topology changes in open-shortest-path first (OSPF) and intermediate-system-to-intermediate-system (ISIS) networks with a minimum number of routing table calculations. This method allows a router to correlate the received Link State Advertisements (LSAs) to identify the topology change that led to their generation. The router performs a routing table calculation once the topology change has been identified.
- *Abstract
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Link state routing protocols such as OSPF and IS-IS are commonly used interior gateway protocols (IGP) on the Internet. Each router knows the topology of the network and uses this information to determine the shortest paths to different destinations. When there is a change in the topology of the network (either the failure of a device or the addition of a new device), each router in the immediate neighborhood of the change generates new LSA that are flooded throughout the network, thereby informing all the routers in the network about the topology change. On receiving each such LSA, a router may immediately perform a routing table calculation to update its routes or wait to receive additional LSAs before doing a routing table calculation. Since a topology change typically leads to generation of several new LSAs, immediate routing table calculation on receiving a new LSA may cause a router to perform many such calculations in quick succession, thereby leading to processing overload in the routers that may have other more sinister consequences. The other option to delay the routing table calculation until several LSAs have been received introduces delays in the convergence process that are highly undesirable as well.
- *Principal Investigator
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Name: Seyed Hossein Hosseini, Professor
Department:
Name: Mukul Goyal , Assistant Professor
Department:
- Country/Region
- USA
