Simulator for slow Internet connections
Hi, I was going through the Coding Projects site the other day and spotted that Tor is in need of a simulator for slow connections. I have written something similar as a part of my M.Sc., so I thought I could contribute by adapting my code to Tor's needs. First of all, has there been any progress on the subject (so that I don't double someone's work)? If I understand correctly, these technical things need to be done: 1) allow to alter parameters of an internet connection on one's computer and 2) allow to measure how these affect the performance of a Tor client (by performance I mean the time to download/upload data from/to internet) Is there something that is not mentioned in the description and might need to be taken into consideration? Btw, my code is partly in Java - is that acceptable or should I use something else (C++ perhaps)? And finally, will the code I supply be used by anybody? ;) Best Regards, Maciej Zbierski *** To unsubscribe, send an e-mail to majord...@torproject.org with unsubscribe or-talkin the body. http://archives.seul.org/or/talk/
Re: Simulator for slow Internet connections
On Wed, 1 Dec 2010, Maciej Zbierski wrote: I was going through the Coding Projects site the other day and spotted that Tor is in need of a simulator for slow connections. I have written something similar as a part of my M.Sc., so I thought I could contribute by adapting my code to Tor's needs. First of all, has there been any progress on the subject (so that I don't double someone's work)? Why is this a coding project ? Why don't they just use FreeBSD with dummynet ? *** To unsubscribe, send an e-mail to majord...@torproject.org with unsubscribe or-talkin the body. http://archives.seul.org/or/talk/
Re: Simulator for slow Internet connections
Thus spake John Case (c...@sdf.lonestar.org): On Wed, 1 Dec 2010, Maciej Zbierski wrote: I was going through the Coding Projects site the other day and spotted that Tor is in need of a simulator for slow connections. I have written something similar as a part of my M.Sc., so I thought I could contribute by adapting my code to Tor's needs. First of all, has there been any progress on the subject (so that I don't double someone's work)? Why is this a coding project ? Why don't they just use FreeBSD with dummynet ? I've personally used Linux's NetEM for testing my Tor Circuit Build Timeout learning code: http://www.linuxfoundation.org/collaborate/workgroups/networking/netem It worked well but it has a major drawback in that if you use netem on the same machine as your code is running, you can't do real packet loss simulations because the Linux networking stack hints to the TCP layer that the loss was artificial so that window sizes are not adjusted as they would be in reality: https://www.linuxfoundation.org/collaborate/workgroups/networking/netem#Caveats Getting a patch to disable this behavior would be a great help. Otherwise, I think we need to revise this task on our website to say that we're looking for a Tor network simulator, not a slow network simulator. Easy mistake, I guess ;) -- Mike Perry Mad Computer Scientist fscked.org evil labs pgpL7cD7wyDha.pgp Description: PGP signature
