Assignment 8

                   CS594-ipp05  revised: 11/3/05

Assigned: 10/27/05
Due: 6:00pm 11/9/05 

Objective:  ns chapter 11 

Points: 25

Description:


  To run ns (and xgraph and nam) on the CS linuux lab machines (cetus/hyrdra)
  you'll need to add some things your path and environment, 
    see ~dunigan/ipp05/ns/README

  Use the topology Tcl you created for assignment 7 to build a full ns Tcl
  script based on the information provided in the text, section 11.8, page 270.
  Your Tcl script for now need only produce results similar to that
  in Table 11.2, e.g., agents on nodes s1 and d1.
  Provide command line arguments that are the TCP/Agents for the two flows,
  selecting from Agents  Tahoe, Reno, Newreno, e.g.
      ns chap11.tcl Reno Newreno
  (Careful, agent Tahoe is just Agent/TCP)
  Report bandwidth for each Agent for the following test pairs
         Reno  Reno
         Tahoe Reno
         Reno  Tahoe
         Newreno Reno

  Use the Sink agent's bytes_ variable to calculate final bandwidth.

 Paste all of your results into an ANSWERS file that you submit with your
 documented tcl source code.
 Put all of your files in a directory and then "cd"
 into that directory and from one of the lab machines use ~cs594ipp/594submit
 Protect your directory with "chmod" so others can't profit from your work.


Notes:
You can set Agent/TCP variables for each flow, e.g.
   set tcp0 [new Agent/TCP/$proto0]
   $tcp0 set window_ $tcp_window
or you can set it for all flows by saying
Agent/TCP set window_ $tcp_window

other ns variables of "interest"
tcpTick_    (units seconds)
packetSize_   (mss, units bytes)
window_    (window size, units packets)
nrexmitpack_ (retransmitted packets)

and on sink   bytes_    (bytes received at sink)

for Vegas
Agent/TCP/Vegas set v_alpha_ 2
Agent/TCP/Vegas set v_beta_ 4
Agent/TCP/Vegas set v_gamma_ 1

for each link you must set the queue size, e.g. between r1 r2, r2 r3, r3 r4
 $ns queue-limit $r1 $r2 $qsize