This QoS math and the recommended values is something I struggle with as well... First off, you have to remember that with the GTS commands the CIR is given in bits and the BC/BE is in bytes. Once you've converted that you'll take the CIR x 1.5 for the recommended BC value.
2000000 / 8 * 1.5 = 375000 I'm not sure where the BE value comes from but based on the answers I've seen I use BC x 2 as you saw in the solutions guide. On Fri, Jan 14, 2011 at 4:55 PM, Baldwin, Patrick A. <[email protected]>wrote: > Marko, Tyson, > > Quick question if you don't mind. I apologize if this has been explained > before I must have missed it. > > Volume 3, Lab 4, Task 1.4 says Ensure that both R7 and R8 consider this > link to have 2000Kb/s available. configure appropriate bidirectional > rate-limiting on R8. Do not use the MQC. > > When I took this lab, I zeroed in on the fact that this was asking for GTS. > However in the solutions guide, you configured it on the physical link > rather than the PPPoE link that was asked for earlier in task 1.4. > > I am curious what might have clued me in to put it on the physical instead > of the dialer interface? > > But the big question is this, I cannot seem to come up with the numbers you > used for the rate-limiting and I am curious if the proctor/grading script > will be this picky (is it wrong if you don't use the values for BC/BE that > they would?) > > The video on demand lesson for this says: > > AR=access rate = line speed not cir > CIR=target rate for rate limit command > BC=TC*CIR > BE=AR-(TC*CIR) > TC=1/8 sec or .125 sec > > The solutions guide used the command: > rate-limit input 2000000 375000 750000 conform-action transmit > exceed-action drop > > Backing out your numbers from the above formulas, I get a TC of .1875 and a > AR of 1125000 see below, I cant figure out where those numbers would have > come from. Can you shed some light on that for me. > > BC=375000=.1875*2000000 > BE=750000=1125000-(.1875*2000000) > > Thanks > > Patrick A. Baldwin (Alex) > Network Engineering > Colsa Corp., HOSC Contract > NASA , Marshall Space Flight Center > *Office: (256) 544-2089 > ÊFax: (256) 544-8629 > *E-mail: [email protected]<mailto:[email protected]> > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
