Pure p2p architecture no always-on server Arbitrary任意的end systems directly peer-peer communicate peers are intermittently connected and change IP addresses Highly scalable(r扩展的but 2Dcult to manage uct by Weiteng Sun chapter 2-application layer 8/73Introduct by Weifeng Sun chapter2- application layer 8/73 Pure P2P architecture • no always-on server • Arbitrary(任意的) end systems directly communicate` • peers are intermittently connected and change IP addresses Highly scalable(可扩展的) but difficult to manage peer-peer