[ns] send /recv

[Sencun Zhu <szhu1@ise.gmu.edu>]

Hi,all:
   
     I have several things not very clear about ns
1: In ns, there is no actual data transmitting between agents(nodes).What
happens when one agent wants to send data to another one is the sender
directly calls the recv method of some agent( is the receiving agent or
the nearest node downstream to the sender in the route? ), so how can the
delay or bandwidth of the links be effective?

2:  Since the send method just tell should send how many bytes, is it
meaningful for the receiver to write a complicate procedure to deal
with the packet just like in the real world?
Say, in centralized multicast scenario, there are very frequent
joins/leaving, suppose for the managing center, we need  a very big tree
and hash table to manage the group, Do we really need to implement the
tree and the hash table, or how to simulate these things?


thank you for any suggestion.


SC