The question is : "What happen when a node is created?"

As I am peeling the layer of Ns-2, after initialization of Ns-2 simulator, the next step would be to create a node. So the question that one should be asking is "What happen when a node is created?"

Actually a node is comprises of classifier objects. The node itself is a standalone object in oTcl. There are 2 types of nodes, an unicast node and a multicast node. An unicast node comprises of address classifier (classifier_) and port classifier (dmux_).

A node will contain an address that will be increased montonously from the initial value of 0. It will also a list of all connected neighbors.

So what the classifier is for?

The classifier will sit in the node and will have the following :

• all the agents connected (eg. Tcp, sink, ...)
• a node type identifier (type of node)
• a routing module (what type of routing method is used eg. unicast, multicast, etc)