FreeBSD 4.9 and TCP

[Kevin D. Kinsey, DaleCo, S.P.]

wilsonb wrote:

>Good Morning,
>
>My name is Brian Wilson and I am currently studying computer science honours
>at the University of the Witwatersrand in Johannesburg South Africa. As part
>of our honours course we have to conduct some small scale research projects.
>
>A number of us are in the position of having to use your FreeBSD product. We
>are however having some difficulties in finding out whether or not it is
>actually the correct product to be using and we have been unable to find the
>necessary information in our numerous searches of the Interent.
>
>  
>

Well, of course it's the correct product ... for me, anyway ;)....

>We have to run tests on different versions of TCP, to measure performance
>issues and the like.
>
>What I would like to know from you is the following :
>
>1) Which versions of TCP does the FreeBSD 4.9 distribution support and
>implement -- we need to use TCP Reno, NewReno, Tahoe, SACK and T/TCP in our
>experiments.
>
>2) How exactly do we change the installation of FreeBSD to enable each of
>these TCP types -- if you tell us where to look and what we need to change it
>would be great
>
>Essentially, what we need your help for is to find out exactly which versions
>of TCP FreeBSD 4.9 is capable of using (seding and receiving) as well as how
>to implement each of them separately.
>
>If you could tell us what to do or at least where to look to find this
>informaiton, it would be greatly appreciated.
>
>Thank you
>  
>

Hi, Brian ...

First, I think I'm supposed to give you an obligatory tweak on
the nose, something to the effect of "do you really want us all
to do your homework for you, so you have more time to drink
and chase women?" :-D

Secondly, I must admit to being first and foremost a (GOAM)
Geek Of Another Major, and therefore not qualified to answer
very many of your well phrased questions.

However, note the following message, entitled "backport of
TCP SACK to -STABLE" posted to the freebsd-stable
mailing list about 36 hours ago by Marko Zec and quoted
in near entirety here:

"I've prepared a more or less blind backport of the TCP SACK code which was 
recently introduced in -CURRENT.  Didn't put the patch through lots of 
testing, but it just seems to work...  The patch is available from the URL 
bellow and should apply cleanly against both 4.10-RELEASE and -STABLE."

http://tel.fer.hr/zec/BSD/4.10-sack.diff


[[Please note that discussion has ensued about whether or not
this code should be used in this way (ie, merged into the -STABLE
tree, which for a little while is still the 4.x branch.  But maybe 
you could test it for him, eh?]]

I'm not much of a programmer, but a quick perusal of this diff
clued me in on at least some of your questions in regard to 4._10_
vs 5-{{NEARLYSTABLE}}*.  I'll leave the rest of the exercise up to you;
as you are studying 4.9**, it may be a simple exercise in exclusion....

And, of course, there really are some good hackers reading these
lists who may tell you everything you wish to know ...

Kevin Kinsey
DaleCo, S.P.

*FreeBSD is readying itself for a big change, the discussion of
which is beyond the scope of this document, but available on the
project's fine website at www.freebsd.org....

**If you are "in the position of having to use" FreeBSD, why not
something more modern, like 4.10 or 5.2.1?  Or, if you have time,
5.3 is scheduled for release in 6-7 weeks or so....