CSE322 Offline 2-Distance Vector Routing Solution

In this assignment, you will modify a given template (JAVA) to simulate simplified version of “Distance Vector Routing (DVR)”.
1. A topology of routers is given as an input in topology.txt. File input/output is managed in the template. The topology contains the list of connected routers (routerId) and IP Addresses of all interfaces against each router. The first interface given in the file is always dedicated for connecting end devices.
2. Open Constants.java. There are two defined constants. One is INFTY which models the infinite distance. The other one is LAMBDA, used to define the rate of altering the state of routers (A functioning router might be switched off or a router which was switched off might be turned on). LAMBDA must be within [0,1]. The higher the value is, the more router state changes will occur. An instance of RouterStateChanger.java does the job for you.
3. A server (NetworkLayerServer.java) first reads the topology and lists the interfaces of routers to connect end devices (client). Each interface is a key in clientInterfaces map, where the value represents the number of end devices connected to that interface (initially
0).
4. While reading the topology, the server creates instances of Router. You have to modify Router.java to complete its functionalities. More specifically, you need to implement the following:
/*
Initialize the distance (hop count) for each router.
For itself, distance = 0; for any connected router with state=true,
Otherwise, distance = Constants.INFTY;
*/ public void initiateRoutingTable() {
}
/*
Delete all the routingTableEntry
*/
public void clearRoutingTable() {
}
/*
Update the routing table for this router using the entries of Router neighbor */ public void updateRoutingTable(Router neighbor) {
}
5. In NetworkLayerServer.java, you will implement an algorithm which can be considered similar to DVR. The pseudocode is given below:
while(convergence) {
/* convergence means no change in any routingTable before and after executing the following for loop for each router r starting from the router with routerId = startingRouterId, in any order */ {
1. T <- getRoutingTable of the router r
2. N <- find routers which are the active neighbors of the currentrouter r
3. Update routingTable of each router t in N using therouting table of r [Hint: Use t.updateRoutingTable(r)] }
}
8. Your task is to enable the client adjusting NetworkLayerServer.java and ServerThread.java for the tasks given as pseudo-code below. Remember, you have major works to do for the tasks in ServerThread.java.
Receive EndDevice configuration from server
[Adjustment in NetworkLayerServer.java: Server internally handles a list of active clients.]
for(int i=0;i<100;i++) { Generate a random message
if(i==20) {
Send the message to server and a special request "SHOW_ROUTE"
Router assigns a random receiver from active client list [Adjustment required in ServerThread.java].
Display routing path, hop count and routing table of each router [You need to receive all the required info from the server in response to "SHOW_ROUTE" request]
}
}
else {
Client sends the message to Server, which [Adjustment required in
ServerThread.java] assigns a random receiver from active client list.
}
If server can successfully send the message, client will get an acknowledgement along with hop count. Otherwise, client will get a failure message [dropped packet]
Report average number of hops and drop rate
9. Use instances of Packet.java for sending and receiving messages or requests. You can insert, update, delete any attribute of Packet class if required.
10. Finally, write a report comparing
• average number of hops and drop rate for LAMBDA = 0.01, 0.05, 0.10, 0.25, 0.50, 0.80. Just show the stats in a table, nothing else.
• Apply simpleDVR() instead of DVR() keeping LAMBDA = 0.10 and compare how drop rate changes because of implementing split horizon and forced update. Briefly put your reasoning.
Please find your offline demonstration video at https://rb.gy/yakbti. While you are highly encouraged to discuss with your peers, ask help from teachers, and search relevant resources online, under no circumstances should you copy code from any source. If found out, you will receive full 100% penalty.