On 3/9/06, Augusto Neto <[EMAIL PROTECTED]> wrote: > Hi, > > The reasons for configurarion fo the RED parameters given by Mrs. Sally > Floyd, as could see, takes into account the queue management goal. Decisions > about the dynamically set of the weights are not clear in the text, at least > considering QoS. Moreover, it is older than the DiffServ :-) that was > standardized in 1998.
That's right. Its goal is to have a proper queue management, and it did not address about the parameter settings dynamically. However, I became to understand how I set the parameters dynamically by reading the article. > My problem concerns on choosing the correct value to set the per-queue > weights according to the bit rate of a flow. For instance, my work consider > that before the adimition of a flow it is necessary to reserve resources for > it, its bit rate in the case. So, if the bit rate is 3Mb I need to configure > the scheduler to reserve 3Mb. In ns-2 the reservation concerns in setting > the weights correct? > RED is exceptionally parameter senstive, and it is hard to say which values are right for a particular case, as you may know. There are normally 4 important parameters though. 1) max thresh: maxthresh = queue_size / 2 2) min thresh: minthresh = maxthresh / 3 3) max_p: max_p = 2 * packet_loss_rate 4) q_w: no definitive answer, but it is almost fine if you leave it to 0.002 (ns-2 default value) This is regarded as a general rule to set the RED paramemters for a simulation, but not for the real world. Soo-Hyun > Regards > > Augusto > > ----- Original Message ----- > From: "Soo-Hyun Choi" <[EMAIL PROTECTED]> > To: "Augusto Neto" <[EMAIL PROTECTED]> > Sent: Wednesday, March 08, 2006 3:59 PM > Subject: Re: RED parameters configuration > > > > Hi, > > > > I think you'd better read this. > > http://www.icir.org/floyd/REDparameters.txt > > > > Soo-Hyun > > > > On 3/8/06, Augusto Neto <[EMAIL PROTECTED]> wrote: > >> Dear Soo > >> > >> I need to choose the correct value for weights of RED queues in DiffServ. > >> For instance, what is the correct value of the weights to be configured > >> for > >> a flow with 1Mb of bit rate? > >> Regards, > >> > >> Augusto > >> > >> ----- Original Message ----- > >> From: "Soo-Hyun Choi" <[EMAIL PROTECTED]> > >> To: "ben" <[EMAIL PROTECTED]> > >> Cc: "ns-users" <ns-users@ISI.EDU> > >> Sent: Tuesday, March 07, 2006 4:00 AM > >> Subject: Re: [ns] RED queue grows beyond limit on ns-2.28-9 > >> > >> > >> > > >> > You need to set the queue size by modifying the following two lines. > >> > > >> > $ns queue-limit $node_(r1) $node_(r2) 100 > >> > $ns queue-limit $node_(r2) $node_(r1) 100 > >> > > >> > > >> > On 3/7/06, ben <[EMAIL PROTECTED]> wrote: > >> >> Hi Soo-Hyun Choi, > >> >> > >> >> I attached the output of the xgraph in ps format. > >> >> 1. red.ps - red.tcl run on ns2.27 in fedora core 4 > >> >> 2. red2.ps - the same red.tcl on ns2.28 in fedora > >> >> core4 > >> >> > >> >> In previous post, I wrote the limit is 100. It is > >> >> mistake, it is infact limit_ is equals to 25. > >> >> > >> >> > >> >> In the first part the current queue is below 25 > >> >> packets. However, in the second part, the red queue > >> >> just grow beyond 25 packets. > >> >> > >> >> > >> >> Cheers, > >> >> > >> >> > >> >> --- Soo-Hyun Choi <[EMAIL PROTECTED]> > >> >> wrote: > >> >> > >> >> > The instantaneous RED queue size shouldn't grow > >> >> > beyond the actual RED > >> >> > queue size, and the average RED queue size shouldn't > >> >> > grow beyond the > >> >> > maxthresh. > >> >> > > >> >> > You may want to check your parameters again. > >> >> > > >> >> > On 3/7/06, ben <[EMAIL PROTECTED]> wrote: > >> >> > > > >> >> > > Hi ns users, > >> >> > > > >> >> > > I some doubt about the RED Queue. I run a > >> >> > > simple tcl script ( can be download from > >> >> > > http://nile.wpi.edu/NS/Example/red.tcl) for RED > >> >> > queue > >> >> > > with 2 TCP sources. I observed that the RED queue > >> >> > just > >> >> > > grow beyond the limit (it is set to 100 packets in > >> >> > the > >> >> > > tcl script) when run on ns-2.28, ns-2.28 with > >> >> > eurane > >> >> > > extension and ns-2.29 . > >> >> > > > >> >> > > It is perfectly ok when run on ns-2.27 and ns-2.26 > >> >> > > with eurane extension. Any comment on this? > >> >> > > > >> >> > > p/s: I'm using fedora core 4 and cygwin on windows > >> >> > > > >> >> > > Ok cheers, > >> >> > > > >> >> > > Ben > >> >> > > Master Student. > >> >> > > > >> >> > > Send instant messages to your online friends > >> >> > http://uk.messenger.yahoo.com > >> >> > > > >> >> > > > >> >> > > >> >> > >> >> Send instant messages to your online friends > >> >> http://uk.messenger.yahoo.com > >> >> > >> >> > >> > > >> > > >> > >> > >> > > >
