Link State Routing Simulator

The goal of this project is to demonstrate the working of link-state(LS) networking routing technique using this simulator that uses Dijkstra's OSP algorithm.

Basic Requirements

Each node should:

1. Generate LS packet with each packet containing the identities and costs of its attached links. (Assuming that each node already has this information stored in a file. In real networks, initially every node will explore its direct neighbors and generate a local topology.)

2. Broadcast LS packets to all adjecent nodes in the network of that LSNode. The result of the nodes' broadcast is that all nodes have an identical and complete view of the network.

3. Each node can then run the LS routing algorithm and compute the same set of least-cost paths as every other node. (For this project, it uses the Dijkstra's algorithm). When the LS algorithm terminates, each node should display the resulting least cost path and forwarding table.

Implementation (Java)

For each of requirements above:

1. LS packet is generated through a LSNode instance using a configuration file that is passed to the constructor. the file contains all the sufficient information to build its own topology and connection information for its adjacent LSNodes in the network. The topology is basically a directed weighted graph stored in the LSNode and can expand easily by adding more nodes on the fly by running them on the network.

2. Broadcasting the LS packets is basically done by a LS routing processor that runs a server that will be acting as the communicator about current LS link with other links that request the graph topology. In addition to a client communicator that requests the network topology from all of its intermediate connections.

3. Each LSNode will run Dijkstra's algorithm when a toString method is called on the LSNode, as it will build the shortest path from LSNode to all LSNodes that are saved in its local graph. This allows the user to view the changes that are happening over that time when the LSNodes in the network communicate with each other with their own topology and expand overtime, this program allows that easily by running a new LS Routing Processor instance with its own settings, as it will broadcast its information easily and dynamically over the network. So no worries about concurrency and expansion at all :)

How to Run

1. Add LSNode settings file that follows the following scheme (updated scheme always in smaple.data):

LSNode ID
LSNode Server Port

number of nodes
<List them with their server port>

number of edges
<edge from U node to V node with W weight>

Sample File:

0
30000

2
1 30001 2 30002

2
0 1 1
0 2 6

2. Run the program with an argument containing the name of the LSNode settings file. This will act as a single node in the network and you need more to build you're own network.

3. Each LSNode now will communicate with its adjacent nodes and communicate with each other, you can always view the topology and GUI of the local graph of each node by sending 1 as a command..

Example

Have a look at "Graph.gif" that has implementation with its "0.data" to "4.data" files.

This following video shows how it is working and communicating with each other.

Contribution and Special Thanks

• Zack Zaiter (Abdulrahman): Programmer.
• Ryan Casiglione: Emotional Support Specialist and discussions invoker.
• Thanks to Dr. Poonam for this great project idea to explore our skills in programming and networking.