change switch model in multicast

[Jaehee Yoon]

Dear NS user group,

I'm trying to change the switch model from end-to-end to hop-by-hop 
basis in multicast. In my network model, each intermediate node should 
store some information about its children, e.g. the next 
hops of the node in the multicast tree, and etc. In this case, I think 
that the transpot protocol needs to communicate with the IP layer 
in the intermediate node, and it will be multicasting. I couldnt't find 
enough documentation of the multicast internal, so I don't know which 
part of the codes I have to change. 

* Recompiling of ns-2
I changed some of the files in the ns-2 directory, and recompiled it 
with 'make'. (I didn't make big change, I just added more variables 
to *.cc files for testing.) It was compiled successfully, but  there 
is a problem executing NS simulator. Whenever I execute ns with the 
command 'ns example.tcl',  I got the following error message.

invalid command name "Simulator"
    while executing
"Simulator create _o1 "
    invoked from within
"catch "$className create $o $args" msg"
    (procedure "new" line 3)
    invoked from within
"new Simulator"

I installed the simulator from ns-allinone-2.1b4a at first time.

Any help would be appreciated.

Jaehee