From: Alexei Monastyrnyi (alexeim@orcsoftware.com)
Date: Tue Oct 24 2006 - 14:46:32 ART
Hi Wincent.
When adding to Bc we definitely increase Tc with the same CIR... but
under the hood... Odom in DQOS Guide says "shape average" behavior is
the same as normal GTS behavior, i.e spending Be after "a long period of
inactivity" during which Be is being accumulated, whereas "shape peak"
spends tokens from Be on every Tc.
If we spend tokens from Be at each and every Tc and our traffic profile
is not lower than conform rate, i.e >=CIR all the time, where do we get
Be accumulated from?
I have a feeling that this Be is not the same as normal traffic-shaping
Be... It is just a sort of extra credit we've got to be able to burst
more at each Tc ... without increasing a Tc...
Does it make any sense?
A.
Vincent Mashburn wrote:
> This is a common question. To answer the question, refer back to the
> formula: CIR = bc/tc.
>
> For shape peak, bc + be is sent every interval, but the formula is still
> CIR = bc / tc. For shape average, bc is sent every interval, and the
> formula is still CIR = bc / tc.
>
> So, say you have a CIR of 64000, bc = 8000 and be = 16000.
> Using shape average:
>
> 64000 = 8000 / tc ==> tc = 125ms.
>
> Using shape peak:
>
> 64000 = 8000 / tc ==> tc = 125ms
>
> Using shape average by setting bc = bc + be
>
> 64000 = 24000 / tc ==> tc = 375ms.
>
> So, as you can see, it is different.
> Hope this helps.
>
> Vince Mashburn
> Voice / Data Engineer
> 901-263-5072
> CCVP, CCNP, CCDA,Network +
> Cisco IP Telephony Support Specialist
> Cisco IP Telephony Operations Specialist
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Cagri Yucel
> Sent: Tuesday, October 24, 2006 4:49 AM
> To: Group study
> Subject: Shape average and shape peak
>
> I am sure I am missing a bit here but on the Cisco Doc it says
>
> shape average sends Bc bits in each interval
> shape peak sends Bc+Be bits in each interval
>
> So what's the point of having a different command ? Isn't it the same
> thing
> if I set shape average with a Bc equal to Bc+Be of shape peak ?
>
> Thanks
This archive was generated by hypermail 2.1.4 : Wed Nov 01 2006 - 07:29:06 ART