ISO 的七层模型是什么？TCP/UDP 属于哪一层？ 1. 网卡，集线器，中继器，交换机，路由器，网管，调制解调器分属哪一层设备？ 2. TCP 协议和 UDP 协议的区别？ 3. 802.1q 是什么协议？ IP 是 5.32.0.0，掩码 255.224.0.0 请问最大的有效地址是多少？ 4. 5. IP 包头几个字节？加上数据部分几个字节？ 6. FTP 下载一个文件完成。有几个 TCP 链接？ 7. 8. 软件测试都有哪些种类？ 9. TCP/IP 通信建立的过程怎样，端口有什么作用？ 10. 翻译： An important feature of smtp is its capability to relay mail across transport service environments. A transport service provides an interprocess communication environment(ipce). An ipce may cover ine network ,several networks,or a subset of a networks. A process can communicate directly with another process through any mutually known ipce. Mail is anapplication or use of interprocess communication. M ail can be communicated between processes in different ipces by relaying through aprocess connected to two (or more)ipces. More soecifically,mail can be relayed between hosts on different transport systems by ahost on both transport systems. 这是其中一套题，有空把另外一套传上来！！！