1.校验和:各数值相加,将溢出位加到最低位,之后将结果取反.若校验和全为0,则说明接收数据正确. 2.停等协议及计算信道利用率:利用率=(L/C)/(L/C+2*传输时延) 3.回退N帧协议(协议5),若保证发送流水线不断,则对序列号位数有要求,帧数=(往返时延+发送时间)/发送时间 4.计算三种协议信道利用率:(1)停等:k=1 (2)回退N:k=2^n-1 (3)选择重传:k=2^(n-1)…

1.以太网使用曼彻斯特编码,效率50% 2.侦听信道时间:来回延时时间(10usec):发送数据(25.6usec): 3.单向时延t=S(距离)/V(电缆传输速率):最小帧长=2*t*C(数据传输速率)——最小帧长问题 4.曼彻斯特中,前高后低表示1,反之0…

题目链接: http://codeforces.com/gym/100114 Description The computer network of “Plunder & Flee Inc.” consists of n servers and m two-way communication links. Two servers can communicate either through a direct link, or through a chain of links, by relayi…

J. Computer Network Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100114 Description The computer network of “Plunder & Flee Inc.” consists of n servers and m two-way communication links. Two servers can communicate either thr…

题目大意:给N个点,求每个点的与其他点距离最大值 很经典的树形dp...很久前就想写来着...看了陈老师的code才会的...mx[x][0], mx[x][1]分别表示x点子树里最长的2个距离, dfs一遍得到. mx[x][2]表示从x的父亲到x的最长路径长度, 也是dfs一遍得到(具体看代码).最后答案就是max(mx[x][0], mx[x][2]). 时间复杂度O(N) ----------------------------------------------------------…

Andrewid the Android is a galaxy-known detective. Now he is preparing a defense against a possible attack by hackers on a major computer network. In this network are n vertices, some pairs of vertices are connected by m undirected channels. It is pla…

https://odzkskevi.qnssl.com/b660f16d70db1969261cd8b11235ec99?v=1537580031 [2012-2013 ACM Central Region of Russia Quarterfinal Programming Contest][J]computer network 题意: n个点,m条边,构成一个无向图,现在让你再任意连接两个点,使得整个图的割边最少. 1 ≤ n ≤ 10 000; 1≤ m ≤ 100 000; 1 ≤ xi…

SDN-based Network Management Solution 摘要: 在此项目中,我们开发了一种网络管理应用程序,以监视和控制由支持OpenFlow的交换机和支持SNMP的设备组成的企业网络. 我们正在利用由控制器集中式软件定义网络控制器旋转的REST接口来运行此应用程序. 我们正在使用的SDN控制器是一个名为OpenDaylight(ODL)的开源控制器. 我们已使用SNMP和OpenFlow南向插件与网络设备进行通信. 为了测试该应用程序,我们在GNS3中模拟了一个网络,该网络…

Computer Network Homework2’s hard question 2. What is the signal which is used to modulate the original signal? A. analog signal B. digital signal C. carrier signal D. base signal (2 points) Answer: C Explanation: original signal指最原始的想要被传给别人的信号 5.In…

Computer Network Homework3’ s hard question 1. Which kind of protocol does CSMA belong to? A. Random Access Protocol B. Take Turns Protocol C. Centralized Protocol (2 points) Answer: A 6. Which provides connection-oriented service? A. LLC1 B. LLC2 C.…