In article <[log in to unmask]>, dated Fri, 17 Jul
1998 at 11:44:15, [log in to unmask] writes
>It is a convenient fiction to think of communication across the
>network as taking place between sub-processes running at the same
>layer level in each of the two systems. It is a fiction because
>the ACTUAL communication is down through the layers in one system,
>across the physical link to the other system, and then back up to the
>corresponding layer in this second system.
My 'Open Systems' knowledge is extremely rusty but I would argue that
what you describe is far from a "convenient fiction", rather it is a
fundamental design concept. Each layer can be in session with its
'opposite number' but have no knowledge of lower intervening layers in
either 'stack'. Thus an application to application session is entirely
unaware of the of the physical transport session (the lowest layer from
memory) going on below.
Chris
--
Chris Salter (Vice Chairman) Lincolnshire Post-Polio Network
Registered Charity No. 1064177
<URL:http://www.zynet.co.uk/ott/polio/lincolnshire/>
Web Site & Vice Chairman Email: [log in to unmask]
Honorary Secretary Email: [log in to unmask]
Member of the British Healthcare Internet Association
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