Subject: [mobile-ip] MIP v6 Regional Registration - identifying requirements

From: Phil Roberts <[email-masked]>
Date: Tue, 3 Apr 2001 11:46:30 -0400

I think I've finally caught up on all the mail about regional registrations
for MIP v6 and HMIP.  There seems to be significant concerns about the task
to be accomplished and the specific approach that is specified in the HMIP
draft.  A short list of concerns include worries about introducing single
points of failure, whether or not multiple levels of hierarchy are needed,
the amount of signaling and tunneling overhead that is implied, the
relevance of load balancing and the particular metrics in the HMIP draft,
and the clarity of the description in the draft.  The participants in the
working group have apparently been thinking a lot about what is actually
needed for a regionalized registration scheme since we adopted HMIP as a
working group draft.

It seems appropriate at this time to have some discussion about what the
requirements for regional registration actually are, then to figure out what
to do about the draft we've chosen as a working group draft.

Here's a short list of requirements drawn from comments received over the
last month or so and from the HMIP draft that the working group participants
can use as a basis for discussion.  Please understand that this is not the
list of requirements I believe are needed but a list of things I've
assembled from drafts and comments on the discussion.  Let's take this list
and try to identify the requirements that everyone agrees to and then have
some discussion about the contentious ones.  Requirements not on this list
are also welcome for discussion.  And reducing or modifying items I've
listed is also open to discussion.

1) Regional registration shall be introduced to minimize the signaling
traffic to the home agent or correspondent nodes for intra-domain mobility
2) Regional registration shall not introduce new overhead on links between
the mobile and the regional registration agents
3) Connectivity to the mobiles shall not be interrupted in the presence of
the failure of regional registration agents
4) Regional registration shall scale to support millions of nodes in a
visited network
5) Regional registration shall be secure against malicious behavior from
visiting mobiles
6) Regional registration shall allow multiple levels of hierarchy
7) Regional registration shall support fast handoffs
8) Regional registration shall not require changes to the mobile node, the
home agent, or correspondent nodes
9) Regional registration shall not introduce host routes in routing tables