A closer look at network structure: □network edge: applications and hosts ▣network core: routers network of networks ▣access networks, physical media: communication links Introduction 1-16
Introduction 1-16 A closer look at network structure: q network edge: applications and hosts q network core: v routers v network of networks q access networks, physical media: communication links
The network edge: ▣end systems(hosts): run application programs e.g.Web,email ÷at"edge of network" ▣client/server model client host requests,receives service from always-on server *e.g.Web browser/server; email client/server □peer-peer model: minimal (or no)use of dedicated servers *e.g.Skype,BitTorrent,KaZaA Introduction 1-17
Introduction 1-17 The network edge: q end systems (hosts): v run application programs v e.g. Web, email v at “edge of network” q client/server model v client host requests, receives service from always-on server v e.g. Web browser/server; email client/server q peer-peer model: v minimal (or no) use of dedicated servers v e.g. Skype, BitTorrent, KaZaA
Wikipedia:Client-Server Client-server computing is a distributed application architecture that partitions tasks or work loads between service providers (servers)and service users,called clients. Often clients and servers operate over a computer network on separate hardware.The client-server model describes the relationship of cooperating processes in an application. The server component provides or service to one or many clients,which initiate requests for such services. Introduction 1-18
Introduction 1-18 Wikipedia: Client-Server q Client-server computing is a distributed application architecture that partitions tasks or work loads between service providers (servers) and service users, called clients. Often clients and servers operate over a computer network on separate hardware. The client-server model describes the relationship of cooperating processes in an application. The server component provides or service to one or many clients, which initiate requests for such services
Wikipedia:Centrlized server-based service model Introduction 1-19
Introduction 1-19 Wikipedia: Centrlized server-based service model
Wikipedia:P2P OA peer-to-peer,commonly abbreviated to P2P,is any distributed network architecture composed of participants that make a portion of their resources (such as processing power, disk storage,files,etc.)directly available to other participants,without the need for central coordination instances (such as servers). Peers are both suppliers and consumers of resources,in contrast to the traditional client- server model where only servers supply,and clients consume. Introduction 1-20
Introduction 1-20 Wikipedia: P2P q A peer-to-peer, commonly abbreviated to P2P, is any distributed network architecture composed of participants that make a portion of their resources (such as processing power, disk storage, files, etc.) directly available to other participants, without the need for central coordination instances (such as servers). Peers are both suppliers and consumers of resources, in contrast to the traditional client- server model where only servers supply, and clients consume