Subject: [Ibnemo] Defining a Common Model for intent

From: "Susan Hares" <[email-masked]>
Date: Sat, 30 May 2015 16:01:53 -0400

On this mail list, there has been a discussion of two types of information
for Intent and Nemo:
(http://www.ietf.org/mail-archive/web/sdn/current/msg00646.html) :

1)      What information is needed to represent a service request, 

2)      How to represent and transport the information for a request.

In order to define what information is needed to represent a 1) service
request that signals Intent from an application to a controller, it is
important to define Intent, and provide a clear model of Intent.  Also, in
describing real use-cases it is important that one uses the same definition
and model for Intent in each use case.   

In the current forums examining Intent (ODL NIC, ODL Nemo, OF NBI and
Keystone, OPNFV Movie, OpenStack) there is a realization that Intent occurs
at multiple layers.  The authors of draft-xia-ibnemo-icim have created a
definition for intent and a unified model for defining intent which can
handle 1 or multiple layers. The model suggest that:

1)      A user has a intent that is expressed in a context.

2)      Intent (usually) involves an object with a result, and optionally
includes operations toward that result. 

3)      Operations conditions perform actions within/modified by
constraints. 

We believe this defines clearly what others are calling "pure intent"
(objects + results) versus "constrained intent" (objects + operations +
constraints).   The draft can be found at:
https://datatracker.ietf.org/doc/draft-xia-ibnemo-icim/ .   The authors are
looking for feedback on the concepts in the draft.   

Sue Hares