If I remember correctly, the formula was:
packets in queue=(packets_in/second - packets_out/sec)*number_of_secs.
So if you have a line that can take 25 packets/sec and you're trying to feed
it 50 packets/sec for 10 seconds, it would be:
(50pps-25pps)*10=250packets in queue over 10 seconds.
Does that sound right?
Thanx,
Mark Baker
-----Original Message-----
From: Michael L. Williams [SMTP:[EMAIL PROTECTED]]
Sent: Tuesday, July 31, 2001 8:49 PM
To: [EMAIL PROTECTED]
Subject: Re: Doubt... [7:14233]
I'm totally speculating here........ Please let me wrong if this doesn't
jive....... it seems to me that the number of packets in the queue
(outgoing) wouldn't be anymore for 50% or 99% until there are more packets
attempting to go over the wire than is allowed.... (i.e. there won't be any
use for the queue except in passing as the packets are sent out as fast as
they are coming to the interface to be sent out).......
I read Jenny's post and I agree with her that utilization is = packets/some
amount of time...... and that things tend to get bursty, etc..... so if
depends on if you're looking at a 1 sec avg. or a 1 minute avg. utilization
as to whether a ping at any given moment would actually go through as fast
as any other time.
Mike W.
"Priscilla Oppenheimer" wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> The number of packets in a queue on a packet-switching device increases
> exponentially as utilization on the output port increases.
>
> Queue depth = utilization/(1 - utilization)
>
> So, do the math. If utilization is 90%, there will be more packets in the
> queue than if utilization if 50%.
>
> That's how I learned it, but it's probably more complex than this....
>
> Comments, anyone else?
>
> Thanks
>
> Priscilla
>
> At 10:41 AM 7/30/01, anil.philip wrote:
>
> >Dear Priscilla,
> >
> >I have a small doubt. I think you are the best person to ask about. May
be
> >you think this as a stupid question. but this is making me crazy.
> >
> >If there is a serial link b/w two sites, at what point of % utilisation
> >the response start degrading???
> >
> >Ideally if I have a T1 link, i shud get the same ping response time
> >till the load on that link is 100%???
> >
> >When I say a T1, it is 1.55 M packets /s. So if the link is utilised for
> >99% (say 1.50Mb..) still I have
> >0.05 Mb left on that link and I shud be able to get a ping (32byte)
> >response time, equivalent to 0% utilisation. Why the response time start
> >degrading at some point of % utilisation??
> >Let us assume there is no packet drop, memmory prob, enough buffer space
> >etc....
> >
> >Request to do a REPLY ALL this email.
> >
> >
> >Regds,
> >Anil Philip
> >AT&T Solutions.
> >anil.philip
> >e-mail: [EMAIL PROTECTED]
>
>
> ________________________
>
> Priscilla Oppenheimer
> http://www.priscilla.com
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=14482&t=14233
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