COMP 189 Lecture Notes - Lecture 1: Internet Protocol Suite, Connectionless Communication, Simple Mail Transfer Protocol
23 Jan 2018
School
Department
Course
Professor
Document Summary
2. what is web : linke connectivity, physical connectivity. Bit=unit of digital information is a bit -like the alphabet for computers. +1laptop 1mbps(can get very low bandwidth 5kbps,2hbps) a router (with maximum ability of carrying data is 10mbps) 4. how is a webpage actually sent? content(text,image,video)>>>cut up into millions of tiny pieces>>>packets. "a packet" all computers know and deliver packets. 1)packets of a content can be sent through any server machines before being sent to the laptop. Tcp/ip=transmission control protocol/internet protocol: is responsible for finding the problems during transmissions, once it find some packets are lost,it will request for sending the missing package again, guarantee the delivery. Udp/ip=user datagram protocol/internet protocol: doesn"t guarantee the delivery. 2: best effort, is easy to lose data. sometimes packet is missing while we can still get the information. Just like facetime ,we hear the sound but cannot see video"s motivation: we can use it under bad internet connection, cause it"s faster and cost less bandwidth.
