Subject: [Roll] DT Update

From: Tim Winter <[email-masked]>
Date: Tue, 02 Jun 2009 13:15:26 -0400

WG,

A brief update on how the design team effort is going-

We are proceeding with the approach that routing metrics will be used to
define an underlying gradient, fixed at some root node upon which links
can be oriented and paths constructed.  The root may typically (but not
necessarily always) be an LBR.  The ability to then construct paths
toward a root that minimize cost (i.e. `shortest', `best') provide a simple
way to support a main type of traffic flow (data collection) as called out
in the various application requirements.  We are hashing out remaining
details as to how constraints are best taken into account, e.g. are they
intrinsic in the construction of the gradient(s), or once a gradient is
defined in a way that provides a global reference to the network are the
constrained paths then further defined with reference to the gradient.

We are having further discussion about the mechanisms to be used to support
others of the typical traffic flows within the LLN, in particular the use
and trade-offs of source routing and hop-by-hop routing techniques.

There is a text evolving as the DT efforts proceed, and it is our goal to
be able to give a -00 version for your review and comment in the next few
weeks, such that some input and feedback from the WG may be collected
and incorporated in time for the next IETF.

Regards,

-Tim