What's the Internet:“nuts and bolts'” view PC millions of connected mobile network 目 server computing devices: OLSTON wireless ·hosts=end systems global ISP laptop smartphone ·running network apps home communication links network regional ISP wireless ■fiber,copper, links radio,satellite wired links transmission rate: bandwidth Packet switches: router forward packets (chunks institutional network of data) routers and switches Introduction 1-4Introduction What’s the Internet: “nuts and bolts” view millions of connected computing devices:  hosts = end systems  running network apps communication links  fiber, copper, radio, satellite  transmission rate: bandwidth Packet switches: forward packets (chunks of data)  routers and switches wired links wireless links router mobile network global ISP regional ISP home network institutional network smartphone PC server wireless laptop 1-4