Em 30-05-2014 08:43, Henning Brauer escreveu: > * Paco Esteban <p...@onna.be> [2014-05-29 12:11]: >> On Thu, 29 May 2014, Marko Cupać wrote: >>> On Wed, 28 May 2014 21:40:58 +0200 >>> Henning Brauer <lists-open...@bsws.de> wrote: >>>> I'm pretty damn sure I added "reset prio if queueing is on" thing. >>>> >>>> yes, in IF_ENQUEUE -> hfsc_enqueue >>>> m->m_pkthdr.pf.prio = IFQ_MAXPRIO; >>> I would like to give priority to certain traffic, for example: >>> prio 7: tcp acks >>> prio 6: domain >>> prio 5: ssh-mgmt, vnc, rdp >>> prio 4: web >>> prio 3: smtp, imap, pop >>> prio 2: ftp, ssh-payload >>> prio 1: default/other >>> prio 0: p2p >>> But I would also like to guarantee minimum bandwidth to low-priority >>> traffic (in upper example I would like to avoid ftp coming to a >>> grinding halt in moments when higher priority traffic eats up all the >>> bandwidth). >>> I thought I knew how to achieve this, but now I am not so sure. Is it >>> possible with current pf? Any suggestions? >> I'm also interested in this. I tought I was doing it with the example I >> sent but, after Henning's comments ... > let's think it through. > prio has really only a non-neglible effect when you are bandwidth > constrained. > with bandwidth shaping (hfsc underneath), you don't want to overcommit. > thus, you are priorizing by picking what traffic goes to what queue > and what bandwidth setting those have. > mixing in another priorization would have zero (or close to zero) > effect. > > so giving you an extra prio button there would probably make feel you > better (like in other implementations), but (also like the others) > have no or close to no effect. > >From my experience, if you have an asymmetric link, where your download rate is bigger than your upload rate, you can see benefits in putting hfsc in front of it. And, the most benefit seems to be on the upload side. There are some factors that weigh in, such as router buffers and network congestion outside of your own network. Speaking of such, I read recently the Codel spec: https://en.wikipedia.org/wiki/CoDel, I don't know if it really helps the bufferbloat problem, but this is another matter entirely, perhaps Henning could explain better, even if it should or not be put into pf.
Now, when you have a symmetric link with enough bandwidth (10+ MB/s), which by the way, depending on the technology used, have little or no buffer at all, them prio will generally do the job, even with p2p applications. Just don't forget there are always nat involved so you need to prio packets all the way, just as you should with hfsc. I find that using tags is the most effective way to do so. Cheers, -- Giancarlo Razzolini GPG: 4096R/77B981BC
