Industry standard bandwidth guarantee?

Rafael Possamai rafael at gav.ufsc.br
Thu Oct 30 18:21:41 UTC 2014


You can't just ignore protocol overhead (or any system's overhead). If an
application requires X bits per second of actual payload, then your system
should be designed properly and take into account overhead, as well as
failure rates, peak utilization hours, etc. This is valid for networking,
automobile production, etc etc..

On Thu, Oct 30, 2014 at 7:23 AM, Jimmy Hess <mysidia at gmail.com> wrote:

> On Wed, Oct 29, 2014 at 7:04 PM, Ben Sjoberg <bensjoberg at gmail.com> wrote:
>
> > That 3Mb difference is probably just packet overhead + congestion
>
> Yes...  however, that's actually an industry standard of implying
> higher performance than reality,  because end users don't care about
> the datagram overhead which their applications do not see they just
> want X  megabits of  real-world performance, and this industry would
> perhaps be better off if we called a link that can deliver at best 17
> Megabits of Goodput reliably a  "15 Megabit goodput +5 service"
> instead of calling it a "20 Megabit service"
>
> Or at least appended a disclaimer   *"Real-world best case download
> performance: approximately  1.8 Megabytes per second"
>
>
> Subtracting overhead and quoting that instead of raw link speeds.
> But that's not the industry standard. I believe the industry standard
> is to provide the numerically highest performance number as is
> possible through best-case theoretical testing;   let the end user
> experience disappointment and explain the misunderstanding later.
>
> End users also more concerned about their individual download rate on
> actual file transfers  and not  the total averaged aggregate
> throughput of the network of 10 users  or 10 streams downloading data
> simultaneously,    or characteristics transport protocols are
> concerned about such as fairness.
>
>
> > control. Goodput on a single TCP flow is always less than link
> > bandwidth, regardless of the link.
>
> ---
> -JH
>



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