Can I join in?
> From: "Ahmad Risk" <[log in to unmask]>
> Subject: Re: Microsoft Exchange
Ahmad suggests the following [there has been a lot of snipping done]
as a mechanism.
> Trust A has connection to NHSnet
> GP B has PC and modem
> What is missing?
>
> Trust A needs:
>
> - keep their existing information systems
> - a web server
> - a protocol that acts as gateway between existing system and
> HTML/SGML (this already exists).
> - a bank of modems
>
> So far, all of the above is either in place or cheap to acquire.
>
> What does GP B need?
>
> - a dial up connection to Trust A's Intranet (TCP/IP)
> - an HTML browser
>
> Both are also very cheap and available now.
>
> The exchange of information:
>
> a) Trust A 'publishes' the path results as they are onto the intranet,
> ie, in which ever format the existing system produces them, only in
> HTML format (no need here for edifact at all) :-)
>
> b) GP B dials up (securely and all that) and logs on to his 'authorised'
> area of access and views or downloads his results.
>
> What we have here is an Extranet between Trust and GP with NHSnet
> providing a very useful infra structure.
>
> 3. The information remains (underlined) within its applications and
> with the owner who has responsibility for its security. In other
> words, the Web becomes the agent between servers and applications.
>
> 4. The key word here is 'applications'. Keep thinking applications
> and you will see it.
Can I suggest an alternative way of describing what Ahmad has
described. What we do is to keep exactly one location at which the
VALUE of a piece of information is held (by 'value' here I am
referring not to monetary worth, but to the content of the location
which holds the value; if we are talking about my weight, the value
is 66Kgm). This location must of course reside with some agency, and
the sensible thing would be to have it reside with the agency which
has undertaken to maintain the value of the piece of information up
to date. All other users of this information do NOT hold the value,
but rather hold a POINTER to the value, and whenever they refer to it
the system will collect the current value from the location pointed
to. [For those who think this way, this is essentially a distinction
between call by value and call by reference for the parameters of a
procedure].
The attractions are simplicity, we all refer to information by the
use of reference, and accuracy, the information is always as up to
date as the agency which maintains cares to keep it. We can still
have all the protection we might need by the use of access control
mechanisms, and encryption; if we are really serious we could even
encrypt the pointers as well.
As I say this is no different from Ahmad's suggestion; just a
different way of describing it.
Mike Wells
==========================================================
Professor Mike Wells
Department of Physics, The University of Leeds
Leeds LS2 9JT, United Kingdom
Phone: 0113-233-3879 E-Mail [log in to unmask]
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