[SGVLUG] Linux based web-server appliance

[David Lawyer]

On Fri, May 19, 2006 at 02:10:20PM -0700, Michael Proctor-Smith wrote:
> You assume that bits on networks are sent serially, but even if
> acctual bits are sent serial depends on network hardware. 

It seems that all network transmission lines are serial.  This
excludes the transmission inside computers and thru parallel cables
from the parallel ports of computers.  So going from-to computers
there is as series-to-parallel conversion.  In olden days (1920's
teletypes) this conversion was done mechanically.

> But bits must be must be checksummed to make sure that they are not
> mangled in transmisstion, so require a block. Plus I don't think
> most or any programs interperate in realtime bit by bit across the
> network. They instead interparte chucks of bits most likely at least
> a int(32bits).

True, but the hardware must transform the serial bit stream into a
byte (or word) stream via serial-parallel conversion.  This was once
done mechanically using a distributor, like on a car.  If you have a
v-8 the 8 wires to the spark plugs transmit a parallel byte, only
instead of spark-plugs you would need  holding relays so that all bits
are present at the same time.  And if the car isn't mission, all bytes
would be FF.

> P.S.  Most OSs are written in C there is a functions with names like
> network_2_host_byte_order and host_2_network_byte_order which you
> should use anytime you are directly preparing data to be thrown
> across the network. This function is a noop if you host byte order
> matches network byte order.

There's also bit order and the convention for it must be universal so
it means the same to all hardware.

			David Lawyer