Subject: [Sipping] draft-ietf-sipping-profile-datasets - datatypes and merging rules

From: "Dale Worley" <[email-masked]>
Date: Mon, 23 Feb 2009 18:00:15 -0500

One aspect of draft-ietf-sipping-profile-datasets that needs clarifying
is how the datatypes and merging rules of profile data elements
(setting) are specified.  The current version uses ordinary XML schema
definitions to define the datatypes of the settings, and that seems
sufficient.  I also expect that a number of common complex datatypes
will be pre-defined in the profile meta-schema, so that profile schema
writers can refer to them by name, rather than having to reinvent them.

I'm still trying to figure out whether XML schema language allows
parameterized data types, so we can pre-define such types as "set of *"
and "sequence of *".

Given that each device will need to discover and load up to 3
overlapping profiles, we need definitive merging rules for each setting.
It seems clear that the place to put the merging rules is in the profile
schema as well.  What is less clear is how to specify the merging rules.

My current thought is that the merging rules should be expressed in
XSLT, because of its compatibility with XML.  I hope that we can
pre-define most of the merging rules that will ever be needed in the
profile meta-schema, so that profile schema writers will rarely have to
write XSLT.

Comments?

Dale