Date   : Thu, 09 Feb 2006 12:10:26 -0000
From   : "David Hunt" <dm.hunt@...>
Subject: Re: Grammar

> > The worst one with respect to this phenomenon is people (most often
> supposed
> > "ICT authorities") who don't understand the difference between a bit and
> a
> > byte, usually in the context of megabits and megabytes, usually with
> > reference to bandwidth indicators.
> >
> > Every time I divide their x megabit download speeds by eight to
> calculate
> > the *real* time for a y MB download they become utterly confused.  This
> > really ought to be the computing equivalent of "learning your abc",
> right?
> 
> Agreed. Problem is that the quoted "bits per second" for most services
> refers to actual bits on the wire, including all protocol overheads,
> rather than bits of "useful data". I believe ADSL IP services in the UK
> run over ATM, which introduces a 10 to 20 percent (dependent on IP packet
> size) overhead before you start. So your 1Mbps service actually gives you
> more like 850Mbps of IP throughput.

Hehehehe, I would like 850Mbps, preferably not on ntl.

You also come across the same marketing spin when purchasing wireless
equipment (WiFi/Bluetooth) where the bit rate given also includes the
"management overhead" for error correction etc. this overhead accounts for
over 50% of the bit rate.

Off topic, I know, but how many people here run wireless networks ? There
are three unprotected networks in my neighbourhood, one of them isn't
firewalled and it's WinXP Home. Perhaps I should do the decent thing point
this out.

Dave ;)