nam.txt

NS的教程

     in this release (v1.0a2).

     Below the gadgets we have discussed so far, there may or may
     not  be  a  Monitor  pane, depending on whether the checkbox
     'View/show monitors' is set. (The  default  is  unset).  All
     monitors  will be shown in this pane. A monitor looks like a
     big button in the pane. Currently only packet and agent  may
     have monitor.
     A packet monitor shows the size, id, and sent time. When the
     packet  reaches  its  destination, the monitor will still be
     there, but saying the packet is invisible.
     A agent monitor shows the name of the agent,  and  if  there
     are  any  variable  traces  associated with this agent, they
     will be shown there as well.

     Below the monitor pane (or in its place if the monitor  pane
     isn't there), there is a Time Slider. It looks like a scaled
     rule, with a tag 'TIME' which can be dragged along the rule.
     It  is  used  to set the current animation time. As you drag
     the 'TIME' tag, current animation time will be displayed  in
     the  time  label  in the control bar above. The left edge of
     the slider represents the earliest event time in  the  trace
     file and the right edge represents the last event time.
     Clicking left button on the rule (not the tag) has the  same
     effect  as Rewind or Fast Forward, depending on the clicking



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User Commands                                              NAM(1)



     position.

     The Automatic Layout Pane can be visible or hidden. If visi-
     ble,  it  is below the time slider. It has three input boxes
     and one relayout button. The labeled input  boxes  let  user
     adjust  two  automatic  layout  constants, and the number of
     iterations during next layout. When user press ENTER in  any
     of  the  input  boxes,  or click the 'relayout' button, that
     number  of  iterations  will  be  performed.  Refer  to  the
     AUTOMATIC LAYOUT section for details of usage.

     The bottom component of the nam window is a Annotation List-
     box,  where  annotations  are  displayed. An annotation is a
     (time, string) pair, which describes  a  event  occuring  at
     that  time. Refer to ns(1) for functions to generate annota-
     tions. Double-click on an annotation  in  the  listbox  will
     bring nam to the time when that annotation is recorded.
     When pointer is within the listbox,  clicking  right  button
     will  stop  animation  and  bring  up  a  popup  menu with 3
     options: Add, Delete, Info. `Add' will bring up a dialog box
     with  a  text input and add a new annotation entry which has
     the current animation time. User can type annotation  string
     in the dialog box. `Delete' will delete the annotation entry
     pointed by the pointer. `Info' will bring out a  pane  which
     shows both the annotation time and the annotation string.

KEYBOARD COMMANDS
     [Incompelete, but accurate] Most of the  buttons  have  key-
     board equivalents. Note they only function when mouse cursor
     is inside the nam window.
     Typing a space or return will pause nam if it's not  already
     paused.   If  nam  is  paused, space or return will step the
     animation one  simulated  clock  tick.   (If  your  keyboard
     autorepeats,  holding  down space is a good way to slow-step
     through some part of the animation.)

     `p' or `P'
          Pause but not step if paused.

     `c' or `C'
          Continue after a pause.

     `b' or `B'
          Descrease animation time for one screen  update  inter-
          val.

     `r' or `R'
          Rewind.

     `f' or `F'
          Fast Forward.




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     `n' or `N'
          Move to next event.

     `x' or `X'
          Undo the last rate change

     `u' or `U'
          Undo the last time slider dragging.

     `>' or `.'
          Increase the granularity (speed up) by 5%.

     `<' or `,'
          Decrease the granularity (slow down) by 5%.

     SPACE
          Toggle the pause state of nam.

     `q', `Q' or Control-c
          Quit

RECORDING ANIMATIONS
     To record nam animations, select  the  ``Record  Animation''
     option  under  the  file menu.  A series of namXXX.xwd files
     will be produced (where XXX is the frame  number),  one  per
     time-step.   These files can then be assembled into animated
     GIFs or MPEGs with the appropriate post-processing tools.

TRACE FILE FORMAT
     The trace file events can be divided into 6 types, depending
     on  to  which object the event is associated. Below, we dis-
     cuss them in detail.

     Packet
          Basic packet events are a type character,  followed  by
          some tags:

                  <type> -t <time> -e <extent> -s  <srcaddr>  -d
          <dstaddr> -c <conv> -i <id>

          <type> is one of:

          `h' - Hop. The packet started to be transmitted on  the
          link from srcaddr to dstaddr
          `r' - Receive. The  packet  finished  transmission  and
          started to be received at the destination.
          `d' - Drop. The packet was dropped from queue  or  link
          from srcaddr to dstaddr.
          `+' - Enter queue. The packet entered  the  queue  from
          srcaddr to dstaddr.
          `-' - Leave queue.  The  packet  left  the  queue  from
          srcaddr to dstaddr.



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          Drop here doesn't  distinguish  between  dropping  from
          queue or link. This is decided by the drop time.

          The flags have the following meanings:

          -t <time> is the time the event occurred.
          -e <extent> is the size (in bytes) of the packet.
          -s <src> is the originating node.
          -d <dst> is the destination node.
          -c <conv> is the conversation id.
          -i <id> is the packet id in the conversation.
          -a <attr> is the packet attribute, which  is  currently
          used as color id.

          Additional flags may be added for some protocols.  This
          list may be extended as required:

          -P <pkttype> gives an ASCII string specifying a  comma
          separated  list of packet types. Some values are: TCP -
          a tcp data packet. ACK - generic acknowledgement.  NACK
          -  generic  negative  acknowledgement.  SRM  - SRM data
          packet.
          -n <sequence number> gives the packet sequence number.


     Link/Queue State

          l -t <time> -s <src> -d <dst> -S <state>  [-c  <color>]
          [-r <bw> -D <delay>]
          q -t <time> -s <src> -d <dst> -a <attr>

          <state> gives the link state transition. It has 3  pos-
          sible  values:  UP  and  DOWN  marks  link  failure and
          recovery, COLOR marks link color change.  If  COLOR  is
          given,  a  following -c <color> is expected which gives
          the  new  color  value.   In  link  event,   [-r   <bw>
          -D<delay>]  gives  link  bandwidth  and  delay, respec-
          tively. It is only used  when  nam  creates  the  link,
          i.e., loading the trace file.
          <attr> specifies the queue position,  i.e.,  the  angle
          between   the  link  along  which  queued  packets  are
          displayed and the horizontal line.


     Node State

          n -t <time> -s <src> -S <state> [-c <color>]

          Flags have th same meaning as those in Link.


     Protocol State



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          Agents can be constructed by:

          a -t <time> -n <agent name> -s <src> -d <dst>

          They can be destructed by:

          a -t <time> -n <agent name> -s <src> -d <dst> -X

          To visualize protocol state variables  associated  with
          an agent, we use the name `feature'. Currently we allow
          three types of features: timers, lists and simple vari-
          ables.  But  only  the last one is implemented in ns(1)
          tracing APIs.

          Features may be added or modified  at  any  time  after
          agent creation using:

          f -t <time> -a <agent name> -T <type> -n <var name>  -v
          <value> -o <prev value>

          <type> is `l' for a list, `v' for  a  simple  variable,
          `s'  for a stopped timer, `u' for an up-counting timer,
          `d' for a down-counting timer.
          -v <value> gives the new value of the  variable.  Vari-
          able  values  are  simple ASCII strings obeying the TCL
          string quoting conventions. List values  obey  the  TCL
          list   conventions.  Timer  values  are  ASCII  numeric
          values.
          -o <prev value> gives the previous value of  the  vari-
          able. This is to allow backward play of animation.

          Features may be deleted using:

          f -t <time> -a <agent name>  -n  <var  name>  -o  <prev
          value> -X


     Misc v -t <time> TCL script string

          is used for annotation, it may  includes  an  arbitrary
          tcl  script  to be executed at a given time, as long as
          the script is in one line (no  more  than  256  charac-
          ters). The order of flag and the string is important.

          c -t <time> -i <color id> -n <color name>

          defines a color. The color name should be  one  of  the
          names    listed    in    color    database    in    X11
          (/usr/X11/lib/rgb.txt).  After  this  definition,   the
          color can be referenced using its id.





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EXAMPLES
FILES
     /usr/lib/X11/rgb.txt

SEE ALSO
     tcpdump(1)

     [1]  Fruchterman, T.M.J. and Reingold, E.M.,  Graph  Drawing
          by  Force-directed  Placement,  Software - Practice and
          Experience, vol. 21(11), 1129-1164, (November 1991).

     [2]  Amir, E., Carta: A Network Topology Presentation  Tool,
          Project   Report,   EECS   Dept.,  UC  Berkeley,  1993.
          http://http.cs.berkeley.edu/~elan/mbone.html

     Mailing lists for nam users and announcements are  the  same
     as   those   for   ns   users.   Send   email  to  ns-users-
     [e-mail]         or         ns-announce-
     [e-mail]  to  join.  Questions should be
     forwarded to [e-mail], ns-announce will
     be low-traffic announcements only.


BUGS
     This manual page is incomplete.






























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