[ns] testing existing tcl to for monitoring

[Florence Oladeji]

Hello sirs. 
I am florence Oladeji (research student) from University of Pretoria. i have on my machine ns-2.30 installed using cygwin.
I want to test one of the existing tcl ns/.../ex/diffserv/ds-cbr-tb-wrr.tcl to monitor the queue at node e1. how do i do this. 
Also, enlighten me more on the difference between 
set numQueues_  1 
setNumPrec 2
in the same tcl. My confusion is that with diffserv more than one queues are used but this tcl only set one queue but two drop precedences.

Thank you for attending to my request in anticipation