From Nsnam
Jump to: navigation, search

This is the archive for the IRC chat on 2008/05/13. Full transcript is below, notes follow.

Participating: Florian, Hagen, Joe, Mathieu, Tom

Major discussion points:

  • Liu has been updating the Wiki w/ Quagga notes
  • Hagen has been working through some parallelizations basics, passing packets through sockets
    • Some discussion about synchronizing w/ Craig's emulation work
  • ns-3 demo proposal was submitted to SIGCOMM by Tom
  • Joe posted some basic draft code outlining the statistics framework


* Now talking on #ns-3
* Topic for #ns-3 is: gsoc: send questions to ns-developers ( if no one answers here
* Topic for #ns-3 set by mathieu_ at Wed Mar 26 12:09:23 2008
* tomh (i=824c2013@gateway/web/ajax/ has joined #ns-3
<tjkopena> hi all
<tomh> hi joe
<tjkopena> hi tom; george mentioned that he wanted to stop by but is at DARPA today and can't join us (not that we had really discussed an organized chat last week)
<tomh> yes, who else besides hagen is here for the gsoc chat?
<tjkopena> all three are logged in, but I don't know if they're actually here
<lacage> morning
<tjkopena> hi lacage
<hgntmp> as I know fw is finish his master theses these days, not sure if he will join us
<hgntmp> good morning to everyone!
<tjkopena> hi hagen
<tomh> good morning
<tomh> I don't know whether LJ__ is joining, but I can give a brief update
<tomh> LJ__ has been developing his plan on the wiki:
<tomh> Mathieu suggested on friday for him to get started by looking at how to support netlink sockets via the process API
<tomh> that is independent of working on the regular socket api which is in flux
<tomh> hgntmp, do you have a plan posted like LJ__ has done (on the wiki)?
<tjkopena> LJ__'s wiki page looks good
<hgntmp> btw: i am _familar_ with netlink sockets for linux (I used this as a transport mechanism some days ago)
<tomh> ok, great-- will let him know
<hgntmp> but as already said: netlink is one of the biggest protocols in the stack - not that easy
<hgntmp> right
<tomh> probably we will support, initially, the pieces needed to modify the kernel forwarding table
<hgntmp> recently I looked in the olsrd implementation, they use nowadays netlinks socket for linux to manipulate them
<hgntmp> (maybe a smooth introduction from userspace side)
<fw_> i'm here.
<hgntmp> moin
<fw_> i sent mail to ns-developers that has the current state of the nsc work
<fw_> i suspect that the mail is pending in the moderation queue, it will hopefull hit the list later today
<hgntmp> got it
<lacage> tomh, hgntmp yes, the goal is to start with only the pieces we need for zebra and these should be relatively minimal.
<tomh> it did hit the moderation queue (I have whitelisted your email for the future)
<lacage> hgn, so, what is the status of your work on the parallel stuff ?
<tjkopena> hgntmp, have you & george been able to hookup & chat specifics?
<hgntmp> really similar to the stuff i wrote to you
<hgntmp> currently i stopped because I need additional information how I can convert this packet class
<hgntmp> the current status:
<hgntmp> i start two ns3 processes and both create a socket, one open, bind, listen and accept()
<lacage> hgntmp, if you have specific questions for me, it would be more helpful to send them to the ML if you can
<lacage> i.e., I am about to answer your email but it would be nice if others could see what you are up to.
<hgntmp> the other one connect with the server socket
<hgntmp> lacage: ok
<hgntmp> afterwards I serialize the packet, get a Buffer instance, PeekData() and write() to the socket
<hgntmp> the client, on the other side, read() the data, build a Buffer and afterwards a Packet instance
<lacage> out of curiosity, why are you actually marshalling the packets through a socket ? do you want your parallel implementation to work on distributed machines rather than a single multicore machine ?
<lacage> (for the latter, you would just need some careful locking, obviously)
<hgntmp> lacage: it was the suggestion from george
<lacage> ah, ok.
<hgntmp> I mean it is still ok, the implementation via shared mem and semaphores (or whatever synchronization is used) could be implemented afterwards
<hgntmp> there are some other fundamental challenges in the area of space parallel appraoch
<hgntmp> especially for wireless (calculation interferences et cetera) 
<hgntmp> but I send my proposal to george and we will discuss these challenges in the next couple of days (after the trip)
<lacage> cool
<lacage> tjkopena, I see that you have started on the ns-3-stat branch. are you going to work on that in the next few days ?
<tjkopena> yes
<tjkopena> so there's an ok sketch in there
<tjkopena> I am going to email vincent & the list later today
<tjkopena> this evening I'm going to clean it up a bit, add another simple example (means) and demo hooking to a trace
<tjkopena> hopefully I can get vincent involved & work on it together
<tjkopena> I only need a couple basic things for now, so hopefully he can pick up on some of the more interesting statistics
<tjkopena> I just 1) needed some of this right now and 2) wanted to make sure it was fairly general, and not tied into specific networking metrics
<lacage> tjkopena, ok.
<tjkopena> if you have comments on that branch I'd be happy to hear them
<lacage> fw_, answered you
<fw_> lacage: thanks, will read it asap
<lacage> tjkopena, I will try to look at it carefully today
<tomh> (reposting-- maybe I missed the response)  hgntmp, do you have any plans posted like LJ__ has done (on the wiki)?
<lacage> fw_, btw, were you able to catch up with sam ?
<lacage> fw_, I understand that 8 in the morning is too early for a googler :)
<tjkopena> lacage, sounds good; there are some design notes in docs/ as well
<hgntmp> tomh: of course - I will do today - I swear! ;)
<lacage> tjkopena, yeah, I saw that
<lacage> tjkopena, did you have comments on my stats email from last week ?
<tjkopena> yes, I thought it was a great writeup
<tjkopena> not too sure on the specifics, but the motivations & goals were good, along with the references
<tjkopena> I was going to crib most of it when I turn the design notes into a larger writeup
<lacage> tjkopena, ok. looks like you are going to write the ns-3-stats paper :)
<lacage> tjkopena, btw, did you submit a sigcomm poster ?
<tjkopena> I did not in the end
<tjkopena> tomh, sorry I did not get back to your email about that
<lacage> tjkopena, ok. tom did submit a demo/poster proposal.
<tomh> hgntmp, once your work starts to get posted, I've asked Craig Dowell to track it as well, since he is working on real-time scheduler and emulation, and is working some multicore issues there too
<lacage> tomh, I replied your last email about sockets
<tomh> it would be nice to harmonize craig's emulation work with your work
<tjkopena> lacage, I saw that.  I may still come out (have to determine that yet), in which case I'd be happy to help w/ the demo & could bring machines (tablets), etc
<tomh> tjkopena, yes I submitted a demo proposal-- did you?
<tomh> I'll send a copy later
<tjkopena> no
<lacage> tjkopena, ok. sounds great.
<tjkopena> but am still thinking about coming out for it
<tjkopena> also, tom (I mentioned this to lacage earlier), I'm coming out to Seattle just before the 4th of July and would be interested in getting together if people have time
<tjkopena> I'm buying air tickets to night & will email everyone
<tomh> great, it is a nice time around here to visit
<lacage> tomh, the beginning of summer :)
<lacage> I am still waiting for it...
<tomh> lacage, we have two more days of winter then you should be happier
<lacage> yeah, I saw the WE forecast
<tomh> lacage, I added a SocketsDefault class last night
<tomh> if you think there is a cleaner approach, we can look at it
<fw_> lacage: yeah
<fw_> lacage: already talked to him about nsc integration stuff.
<lacage> tomh, as I replied, I think that attributes would work.
<hgntmp> I must leave now - for additional info regarding my person I will read the IRC backlog afterwards
<lacage> hgntmp, ok. have a good night
<hgntmp> or email! ;)
<hgntmp> 5:46pm
<lacage> fw_, were you able to setup a regular meeting ? or is this just a couple of emails ?
<fw_> emails and jabber
* hgntmp (i=50f62021@gateway/web/ajax/ has left #ns-3
<fw_> at the moment i send him a weekly status report
<tomh> lacage, well, I am not going to hold up my post to ns-developers for that (which I'm trying to write in parallel to this chat)
<lacage> fw_, ok. if you can and if he is ok with it, it might make sense to send it to ns-dev.
<lacage> tomh, certainly. I will comment on the list.
<tomh> I have not pulled the raw buffer variants.   That will still be controversial despite what we discussed on Friday.  I would prefer to let it lie.
<lacage> what does "let it lie" means ?
<lacage> does it mean that you do not want to do it _now_ ? or that you do not want to do it _ever_ ?
* lacage is curious
<tomh> not reopen the issue
<tomh> I will comment it on the list
<lacage> ok
<lacage> thanks
<tjkopena> ok guys, have to run; will chat later.  thx
* Disconnected ().