Project 4 Solution

Goal



To gain a better understanding of graphs and graph algorithms through practical implementation.


High-level description



Your program will analyze a given graph representing a computer network according to several specified metrics. The vertices of these graphs will represent switches in the network, while the edges represent either fiber optic or copper cables run between the switches. Your program should operate entirely via a console interface menu (no GUI).

Specifications



1.    Your program should accept a single command-line argument that specifies the name of a file containing the description of a graph. Two such files are provided, network_data1.txt and

network_data2.txt . The format of these files is as follows:


The first line contains a single int stating the number of vertices in the graph. These vertices will be numbered 0 to v-1.

Each subsequent line describes a single edge in the graph, with each of the following data items listed separated by spaces.

First, two integers specify the endpoints of the edge.


Next, a string describes the type of cable the edge represents (either "optical" or "copper").


Next, an integer states the bandwidth of the cable in megabits per second.


Finally, an integer states the length of the edge in meters.


As an example, the line 0 5 optical 10000 25 describes an edge between vertex 0 and vertex 5 that represents a 25 meter optical cable with bandwidth of 10 gigabits per second.

Assume that all cables are full duplex and hence represent connections in both directions (e.g., in the example above, data can flow from vertex 0 to vertex 5 at 10 gigabits per second and from vertex 5 to vertex 0 at 10 gigabits per second simultaneously).


    2. You must internally represent the graph as an adjacency list.

    3. After loading the graph from the specified file, your program should present the user with a menu with the following options:

        1. Find the lowest latency path between any two points, and give the bandwidth available along that path.

            1. First, your program should prompt the user for the two vertices between which they wish to find the lowest latency path.
            2. Then, your program should output the sequence of vertices that comprise the lowest-latency path, in order from the first user-specified vertex to the second.

You must find the path between these vertices that will require the least amount of time for a single data packet to travel. For this project, assume that the time required to travel along a path through the graph is the sum of the times required to travel each link, and that the time to travel each link is equal to the length of the cable divided by the speed at which data can be sent (determined by the link type).

Assume data can be sent along a copper cable at a speed of 230,000,000 meters per second.

Assume data can be sent along a fiber optic cable at a speed of 200,000,000 meters per second.


        3. Finally, your program should output the bandwidth that is available along the resulting path (i.e., the minimum bandwidth of all the edges in the path).

    2. Determine whether or not the graph is copper-only connected, or connected when considering only copper links (i.e., whether it is connected when ignoring fiber optic cables).

    3. Determine whether the graph would remain connected even if any two vertices fail.

Note: You are not prompting the user for two vertices that could fail, you need to determine whether there is any pair of vertices that, should they both fail, would cause the graph to become disconnected.

    4. Quit the program.
Submission Guidelines:



DO NOT upload any IDE package files.


You must name the primary driver for your program    NetworkAnalysis.java .


You must be able to compile your program by running    javac NetworkAnalysis.java .


You must be able to run your program with java NetworkAnalysis [data_filename] (e.g., java NetworkAnalysis network_data1.txt ).

You must fill out    info_sheet.txt .


The project is due at the precise date and time stated above. Upload your progress to Box frequently, even far in advance of this deadline. No late assignments will be accepted. At the deadline, your Box folder will automatically be changed to read-only, and no more changes will be accepted. Whatever is present in your Box folder at that time will be considered your submission for this assignment—no other submissions will be considered.


Additional Notes and Hints:



Code for some of the algorithms needed in this assignment has been provided by the authors of your textbook. Use of this code will require extensive adaptations to account for the two weights of each edge in the graph.

The assumed calculation of network latency used here is a drastic simplification for this project. Interested students are encouraged to investigate a more detailed study of computer networks independently (recommended reading: Computer Networks: A Systems Approach by Peterson and Davie).


Grading Rubric



Feature
Points

Menu interface is user-friendly
5

Query

Points
Lowest latency path: sequence of vertices
20
Lowest latency path: bandwidth

10
Copper-only connectivity

25
Surviving 2 vertex failures

35

Other    Points

Assignment info sheet/submission
5