[ns] different RTT over same link????

[Kaleelazhicathu R R Kumar <kaleelaz@comp.nus.edu.sg>]

hi all,
  Is it possible to generate flows having different RTT over the same
link.ie, 
                  L1        
      n1----------------------n2

say if the delay of link is 200 ms,can i create a flow with a lesser
RTT(50 ms) over the same link to simulate a higher priority flow in a
situation of zero queueing delay???
  since the RTT=propagation delay + queueing delay
can i have one flow with RTT and another with only propagation
delay(assuming a higher priority).
  i hope , i have made my question clear.
thanks.
Renjish.