一、因特网与TCP—因特网的协议 二、DNS 三、TCP、UDP

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

一、信道 二、传输媒体 三、编码 四、多路复用 五、数据交换技术 六、差错控制

Network layer functions transport packet from sending to receiving hosts network layer protocols in physical every host, router data link physical data link

TCP segment structure 32 bits URG: urgent data (generally not used) source port #f dest port counting by bytes sequence number

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

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

一、为实时应用程序提供标准化格式的分组 二、一般在UDP之上运行 三、有定义的首部字段如下

MAC协议小结 一、、对于共享介质可以做些什么? 二、信道分割,按时间,频率或编码

一、应用程序和应用层协议 应用程序:沟通,分布式的进程