Chapter 7: Network security Foundations: what is security? crypfography authentication message integrity key distribution and certification Security in practice: application layer: secure e-mail

Summary of mac protocols What do you do with a shared media? Channel Partitioning by time, frequency or code Time Division, Code Division, Frequency Division Random partitioning dynamic

Assignment: read Part I: Introduction chapter 1 in text ur goa Overview: get contex↑ what's the Internet overview.\feel\of what's a protocol?

《计算机网络与通讯》课程教学资源（PPT课件讲稿，英文版）Chapter 3 Transport Layer

7.1 What is network security? 7.2 Principles of cryptography 7.3 Authentication 7.4 Integrity 7.5 Key Distribution and certification 7.6 Access control: firewalls 7.7 Attacks and counter measures 7.8 Security in many layers

IP datagram format IP protocol version 32 bits Imber total datagram header lenath lver/head pe length(bytes) (bytes) Hlen service

Link Layer: setting the context actual PDu flow Router r1 applicatio pp lication transport trar sport network net vork data link

Chapter Overview: understand principles transport layer services behind transport layer 0multiplexing/demultiplexing services: 0connectionless transport: UDP multiplexing/demultiplex

Introduction This chapter describes the general concept of remote file access and reviews the concepts underlying a particular remote access mechanism Because the remote file access mechanism derives many ideas and details from the underlying OS, the chapter reviews the Linux file system and the semantics of file operations

Introduction X Presents the sequence of steps a programmer takes to first create a conventional program and then divide the program into local and remote components w Uses an example application to show the output from rpcgen and additional code required to create the client and server components of a distributed program that uses rpc