[ns] Queues and MACs

[Raju Mansukhlal Shah <rshah@seas.gwu.edu>]

I am in the process of writing my own mac code and i do not know where to
look to answer this question - how does a mac layer put a packet that it
has been told to send back at the front of queue?

the reason i ask this is for the following scenario:

my mac layer can have three states - either send, receive or idle, it can
only send if it is in send, otherwise it cannot. futhermore my mac layer
is using timeslots.

during a timeslot i only want send to be called once and i want to only
pull something off the queue if i can successfully send it (ie my state is
send)

(if there is a piece of specific code please point me to it)

Thanks

raju