[Ns-developers] gsoc wrapup

[Florian Westphal]

Mathieu Lacage <mathieu.lacage at sophia.inria.fr> wrote:
[..]
> Based on the information I have right now, it looks like florian's stuff
> is on track to be merged pretty soon after a couple of final reviews.

This would be great, please poke me via mail or irc if there should be
showstoppers, i'd really like to see it merged and will be happy to
help.

> Before we get to the final evaluation period on monday, I would really
> appreciate that each student try to send a short summary of what they
> have accomplished over the summer.

We have a port of the Linux 2.6.26 stack available in NSC.
ns-3-nsc (ns-3 with additional code that allows a simulation
to assign nsc real-world network stacks to nodes) will then
generate 'proper' pcap TCP traces that can be examined
with wireshark, tcptrace, etc.
I've put up a page with a few tcptrace plots at http://strlen.de/cradle/.
Using ns-3-nsc (with valgrind mem checker) even revealed an obscure bug
in Linux' TCP syncookie mechanism.

The API provided by NSC was extended to allow a simulator
to retrieve a list of supported sysctl values, to retrieve
the IP local/peer ip addresses of a connection and to
check for 'soft' (e.g.EAGAIN) or 'hard' (e.g. ECONNRESET)
errors returned by a stack.

Thanks to Mathieu Lacage ns-3s attribute system can be used to
set sysctl values of a stack, e.g. one can change the TCP
congestion control algorithm to use, disable tcp timestamps, etc.

Sam Jansen made a lot of improvements to the nsc globaliser,
which made porting Linux 2.6.26 much simpler. Also, thanks to his
efforts the development version of NSC is now available via mercurial.

I'd like to thank Sam for being patient with me when explaining NSCs
internal workings, Mathieu for helping out on the ns-3 side of things
and everyone else that helped along the way.

Florian