- May 15, 2020
完成5道计算机网络问题 解析 q1：求B到F的最短路径，利用Dijkstra算法，先求B到邻节点的最短路径，为3（BC），再将BC看成一个节点求他们到其他邻节点的最短路径，为5（BCE），重复步骤，求得B到F的最短路径为7，注意更新节点的权值变化
COMP90007 Internet TechnologiesAssignment 2Semester 2, 2019Due date: Oct 18th Friday 11:30amThis assignment is worth 5% of the total marks for the subject. This assignment has 5 questions.The weighting of each question is shown beside the question. Answers must be submitted as aPDF file via the COMP90007 Assignment 2 submission form in the LMS which will open close tothe submission time. Late submissions will attract a penalty of 10% per day (or part thereof).Please ensure your name, user name and id are clearly presented. Submission should onlycontain the question number and the answer (do not repeat the text of questions in yoursubmission). Questions can be answered by studying the material covered. All work presentedshould be your original individual effort/work.Question 1 (1 mark)Consider a subnet in the following figure, with the weight of each edge as shown in the label.The shortest path routing is used.1) Compute the sink tree for node B using Dijkstra’s algorithm. Show your calculation and thesteps of adding all nodes to the sink tree. (It is recommended to use a table similar to theone as shown on the Slide 9 of Week 6’s lecture)2) What is the shortest path from B to F and its distance?Question 2 (1 mark)Suppose that four organisations A, B, C and D request 2000, 1700, 900, and 4000 addressesrespectively, and in that order. There are a large number of consecutive IP addresses availablestarting at 22.214.171.124, which can be assigned to these four organisations. For each of theseorganisations, give the first IP address assigned, the last IP address assigned, the number ofaddresses allocated and the mask in the w. x. y. z /s notation.Question 3 (1 mark)Different applications care about different aspects of a network transmission. For the followingapplications please annotate each bucket/aspect with three values, Low, Medium, High, whereHigh means a high need for quality for that aspect.Question 4 (1 mark)At Transport layer we use segments to send data across. Argue for using larger segments bydiscussing briefly why larger segments could be beneficial. Then also argue why using smallsegments may be beneficial.Question 5 (1 mark)In the following security protocol that we saw in class, discuss briefly what could go wrong withthe protocol if RA was not sent across from Alice to Bob. What fails in the protocol?