[ns] Memory conservation

[Ishan Mandrekar <ishan@io.ece.drexel.edu>]

Hi,

I'm trying to reduce simulation time by looking at techniques to reduce
memory usage.

I tried disabling unused packet headers in /ns/tcl/lib/ns-packet.tcl, but
that didn't help a lot.

Next thing I'm looking at is to do a delay_bind on the variables. I'd a
look at tcp.{h,cc} and found a comment in the code that says "delay bound
tracevars aren't yet supported". Does this statement still hold true (my
snapshot is about 3 months old). Also, could anyone tell me what exact
code changes need to be made to switch from bind() to delay_bind().

Any other tips for speeding up the simulation r welcome.

-Ishan.