Telematics Chapter 6: Network Layer - Freie Universität Berlin

Open Shortest Path First (OSPF)
● Autonomous Systems (AS)
● The Internet is divided into autonomous systems (AS, 32 bit ID, was 16 bit)
● Each autonomous system has a backbone, which connects all parts of the AS
● Large autonomous systems are divided into areas
● Area of an AS
● Within an area every router has the same link state database and implements
the same algorithm for determination of the shortest path
● Every router, which belongs to two or more areas, is part of the backbone
● A router, which connects two areas, needs the link state databases from both
areas
Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 6: Network Layer
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