[ns] Results interpretation

[Andrea Josi <cmoncharlie@tiscalinet.it>]

Hi everybody,
i've just begun running simulations with NS,
i don't know how to get informations from the
simulations' results; to be more specific:

* how can i read trace files ?
  all the simulations that i've run included a call
  to either NAM or XGRAPH, so the output of the simulation
  was an animation or a graph, i would like to get to read
  something like
  + 1.39117 3 4 exp 1000 ------- 0 0.0 4.0 13 159
  + 1.394 3 4 cbr 1000 ------- 1 1.0 4.0 86 160
  d 1.394 3 4 cbr 1000 ------- 1 1.0 4.0 86 160
  - 1.394 3 4 exp 1000 ------- 0 0.0 4.0 9 147
  r 1.396 3 4 cbr 1000 ------- 1 1.0 4.0 81 145
  + 1.39969 3 4 exp 1000 ------- 2 2.0 4.0 60 161

* XGRAPH : wich quantities can be displayed ?
  for instance, in Marc Greis' tutorial i've found
  proc record {} {....
  ...................
  set bw0 [$sink0 set bytes_]
  ............ }
  Are bytes and packets the only quantities i can record ?
  Can i record the parameters that characterize an agent ?
  (for example, can i record the quantity cwnd of a TCP agent ?)

* NAM : what data can i collect by watching a NAM animation ?
  how do i have to read the sequence of lines that appears
  by clicking on a link and selecting the bandwidth of the link ?

* Am i ignoring other ways to interpret the output of a simulation ?
  If i have to add some lines to my scripts i would appreciate if
  someone sent me some of his own tcl scripts.

Please help me !!!
Thanks in advance,
                        Andrea Josi.