Network Simulation Cradle

VERSION

  0.5.1
  21 September 2009

ABOUT

  The Network Simulation Cradle (NSC) allows real world TCP/IP stacks to be
  used in a simulation environment. It has been primarily used with the network
  simulator ns-2, but is designed to simulator independant.

  More information can be found about NSC at the authors webpage:

    http://www.wand.net.nz/~stj2/nsc/

  If you use this software in any research, please cite this work.
  Use the following publication:

    http://www.wand.net.nz/pubDetail.php?id=215

  Documentation is still pretty lacking at the moment. Email me if you have
  questions and I'll try and add the answers to the documentation in later
  releases.

SIMULATOR SUPPORT

  The NSC supports any simulator that implements the interface in
  sim/sim_interface.h. An ns-2 implementation is shipped with this code and
  ns-3 support is included in the ns-3 project.

  Most of this file is dedicated to ns-2 specific features/limitations.

CONFIGURATION OPTIONS AND COMMANDS FOR NS-2

  The NSC TCP agents have a few commands to allow them to be configured. There
  is one option that should be set before the agents are created, like so:

    Agent/TCP/NSC set autoConf_ 0

  autoConf_ sets whether NSC TCP agents will have their window set 
  automatically to the window_ variable of Agent/TCP. If you leave autoConf_
  enabled and set window_, the NSC implementations will attempt to set the
  correct window size when created.

    Agent/TCP set window_ 50

  MTU size is derived from the packetSize_ variable, so:

    Agent/TCP/NSC set packetSize_ 1500

  Will set NSC TCP implementations to have an MTU of 1500 (and hence an MSS of
  1460 or 1448 or similar).

  Once created there are various commands that may be performed on the TCP
  agents such as 'sysctl'. Eg.

    set stack [new Agent/TCP/NSC/Linux26]
    $stack sysctl net.ipv4.tcp_westwood 1

  Other options can be found by poking around in the source. The above are the
  usual commands and the ones which are well tested.

KNOWN BUGS AND LIMITATIONS

  The stacks are fairly recent, but not the most recent version available.
  Updating is not a difficult task, but requires a bit of testing afterwards to
  make sure nothing is broken. I haven't got around to this for some time
  because I haven't found any great reason to upgrade often. All stacks will be
  updated in the future, but I can't vouch for exactly when.

  There are a few "fudges" in the code to make things somewhat compatible with
  the existing ns-2 TCP models. For example, if you enable tracing ($ns
  trace-all) then the sequence numbers output to the trace for NSC agents will
  be fudged to something reasonable. In many situations they probably shouldn't
  be trusted. The problem here is that a) ns-2 one-way TCP models are one way
  and b) ns-2 one-way TCP models measure sequence numbers in segments, not
  bytes.

  There are probably a host of other things that should be here. I've forgotten
  what they all are.

USAGE

  See the INSTALL file to get it up and running.

  See the example scripts in ns/tcl/nsc/ for information on how to use the NSC
  TCP implementations. In general they are a drop in replacement for the TCP
  models in ns2.

AUTHORS

  Sam Jansen
  sam@wand.net.nz
  WAND Network Research Group
  Department of Computer Science, University of Waikato, Hamilton, New Zealand

CONTRIBUTORS

  Florian Westphal - ns-3 support, Linux 2.6.26, lots of other work
  Various others - email me if you want your name here!
