Re: Traffic Shaping question

Khalid,

First of all please note that for the Be to be filled, few intervals have to
be "silent". Other thing is that packets are always serialized in the Access
Rate.

In your example, if Be bucket is full, packets will be sent for 125ms (first
interval) and at this point there will be 0 tokens in Bc and 1kB tokens in
Be. Then 1kB tokens are added to the Bc which means that traffic will be
sent for another 125ms (second interval) - 62.5 will be sent based on what
is in Bc and another 62.5 based on the Be spare. Finally, third interval
allows to send 62.5 based on what has been added to Bc token bucket. This
all totals to 40kbps.

Regards,

-- 
Piotr Kaluzny
CCIE #25665 (Security), CCSP, CCNP
Sr. Support Engineer - IPexpert, Inc.
URL: http://www.IPexpert.com
On Mon, Mar 22, 2010 at 5:52 PM, Syed Khalid Ali <
khalid_khursheed_at_hotmail.com> wrote:
> hi group:
> Need some clarification how Be works with traffic shaping assuming that
> access-rate=128kbps and shape-rate=64kbps
> To shape traffic at 64kbps, router must send traffic every 128/64=1/2 time
> intervalBc= Tc x shape-rateBc= 125ms x 64kbps = 8kbitsTraffic is forwarded
> every 62.5ms for each Tc (125ms default)Now if Be=16000 bits, the total
> bucket size= 8k + 16k = 24kbitsWhen router start sending traffic, it will
> send:1- 62.5ms for Bc(first interval)2- 125ms for Be3- 62.5ms for Bc(seconds
> interval)since we are already in seconds interval and Bc should have been
> refilled4- 62.5ms for Bc(third interval)since this is the third interval and
> again Bc must have been refilledTotal time=312.5ms Total Traffic=48kbits
> Am I doing it right?
>
> Regards,Khalid
>
>
>
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