Help on using NSE opaque mode

[Jeff Donahoo <Jeff_Donahoo@baylor.edu>]

We compiled ns - emulator on FreeBSD 2.2.8 and successfully ran the 'ping
responder' script.  We are now deciding where to go from here.

Is it possible to use NSE in opaque mode to communicate between real
endpoint programs (both sender and receiver) all on the same machine?  That
is, I would like to write a basic (non-simulated) sender and receiver using
sockets (or whatever) and have their packets traverse a "simulated NSE"
network between each other.  All of the opaque mode sample scripts seem to
assume NSE is running on a machine with multiple Ethernet cards, and the
protocol endpoints are running on other machines that communicate via the
NSE machine (a total of 3 machines).  (Am I misinterpreting?)  We would like
it all on one machine.  Possible?  If so, how?   How about just two machines
using loopback or something?  Any and all input on ideas for using opaque
mode emulation is appreciated.  We hope to use it for classroom instruction
by allowing student programs to experience "real" network dynamics.

Thanks,
Jeff