Is 'dynamic scheduling' in tcl script possible?

[Hyogon Kim <hkim@bellcore.com>]

Hi, 

it seems to me that using NS is like loading a gun and shooting it. By loading I mean 
"pre-scheduling" events using "ns at" in tcl script, and by shooting I mean invoking
"ns run". It doesn't seem that I can schedule events after the ns run (so it's sort of
a point of no return). But isn't this a handicapped feature when simulating, say a
ftp session, where I could transmit multiple files back to back, and the start time of each
TCP connection depends on the duration of the previous connections. I mean when you
can't predetermine the start time of a (TCP) connection, what can you do? Is there some
way to work around this on tcl script level? (I don't really want to tweak the simulation
engine itself except for last resort) Or is it the case I am just missing something? 
In either case, would you please be kind enough to enlighten me?

Thanks a lot,
Hyogon