[ns] Help : Multicast

[Chirdeep Chhabra <Chirdeep.Chhabra@dimail.epfl.ch>]

Hi NS users,
I want to simulate some multicast protocols. If someone has been doing
some simulations in multicast I need some help at the earliest. I have
been trying to simulate a protocol typically :

To atomically broadcast a message m, a process p must wait for the
token. When it holds the token, P broadcasts (all are members of the
group) m to the other processes and passes the token to the next
process. The message m can be delivered (accepted by the upper layed )
only after it has been acknowledged by all processes. The
acknowledgements of messages are carried by the token. So m is delivered
by the last process only after two round trips of the token.

This is one of the simple multicast protocols I need to simulate. Could
you pls let me know if it is possible to simulate such protocols in NS.
I have been trying simulate without much success. If someone has done
something like above of something simpler (acknowledgements to all
members after receiving message etc) pls send me the script. Will I need
to create new agents to do the simulation ??
I would be greatful for any help

sorry for the huge mail
thanks
-chirdeep