Chapter1_2.pdf - Packet switching versus circuit switching Is packet switching a slam dunk winner great for bursty data resource sharing simpler no call

Chapter1_2.pdf - Packet switching versus circuit switching...

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Introduction great for bursty data resource sharing simpler, no call setup excessive congestion possible: packet delay and loss protocols needed for reliable data transfer, congestion control Q: How to provide circuit-like behavior? bandwidth guarantees needed for audio/video apps still an unsolved problem (chapter 8) Is packet switching a slam dunk winner? Packet switching versus circuit switching 1-1
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Internet structure: network of networks End systems connect to Internet via access ISPs (Internet Service Providers) Residential, company and university ISPs Access ISPs in turn must be interconnected. So that any two hosts can send packets to each other Resulting network of networks is very complex Evolution was driven by economics and national policies Let s take a stepwise approach to describe current Internet structure
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Internet structure: network of networks Question: given millions of access ISPs, how to connect them together? access net access net access net access net access net access net access net access net access net access net access net access net access net access net access net access net
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Internet structure: network of networks Option: connect each access ISP to every other access ISP? access net access net access net access net access net access net access net access net access net access net access net access net access net access net access net access net connecting each access ISP to each other directly doesn’t scale: O( N 2 ) connections.
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