network modelling tools?

[Larry Swift]

I'm looking for some easy-to-use simulation and/or modelling tools to use
on the Sun to help with design of networking protocols and high speed
communications platforms.  (I'm not looking for CAD functions such as
schematic capture -- only simulation of data transfer, storage, and
processing, in order to predict throughput performance.)  Does anyone know
of some that require neither extensive simulation experience nor
significant start-up efforts?  Making good use of the Sun's graphics would
be nice, but certainly isn't a requirement.  Built-in standard protocols
would be a more significant feature.

Thanks for any input,

Larry Swift                     UUCP: {peora,uunet}!pdn!larry
AT&T Paradyne, LG-129           Phone: (813) 530-8605
P. O. Box 2826
Largo, FL, 34649-9981           She's old and she's creaky, but she holds!