Folks,
Over the weekend whilst walk the dog, my mind was crunching on the XP
terminology and intermediaries, particularly in regard of trying to
reconcile the different points-of-view on intermediaries expressed in [1,2].
Take a look at the attached 3 slides (GIFs and .ppt). The first is the
Overview slide from the posting I put out to the AMG on Friday [4]. This
places XP Processing Intermediaries firmly above the XP layer, as
application entities - it also shows transport intermediaries down in the
underlying protocols.
The second slide introduces the notion of Application Intermediaries and XP
Messaging Intermediaries, which seems to line up with Scott and Hugo's
postings [3,4]. The former are application entities and lie outside of the
core of XP. The latter are principally XP message routers (analogus to IP
routers in an IP environment). The XP Messaging service would then have to
consider path model through such Messaging intermediaries, but there may
also be implicit paths...eg. consider an initiating device that supports XP
over SMTP addressing an XP message to http://myxp.xp.com/myStockQuote. It
may be configured (proxy style) to send the message via SMTP to a XP/SMTP to
XP/HTTP messaging intermediary.
The second slide sticks with the terminology of the first.
The third slide plays with the terminology - again in a bid to try and
reconcile that with our existing glossary.
I think that getting this overview picture (and the terms it encapsulate)
right is the key to getting our model right.
So... I'd like:
1) your comments on whether the shape of slides 2/3 is preferable to slide
1.
2) assuming slide 2/3 is preferable which collection of offered terminology
seems more comfortable... or offer a new set that better fits your own
comfort levels.
I'd like that we spend some time on Tuesday talking around theses 3 slides.
I'll send a full agenda later today.
Best regards
Stuart
[1] http://lists.w3.org/Archives/Public/xml-dist-app/2001Feb/0005.html
[2] http://lists.w3.org/Archives/Public/xml-dist-app/2001Feb/0007.html
[3] http://lists.w3.org/Archives/Public/xml-dist-app/2001Feb/0006.html
[4] http://lists.w3.org/Archives/Public/xml-dist-app/2001Feb/0011.html
[5] http://lists.w3.org/Archives/Member/w3c-archive/2001Feb/0063.html
