Subject: RE: [manet] Gateway address resolution

From: "Mullen, John P. (Contractor)" <[email-masked]>
Date: Mon, 1 Jul 2002 12:34:18 -0600

Mulling on this,

Suppose we had a MANET implementation of a "cellular" phone system, in which
instead of a backbone of cellular antennas, routers, etc., there is just a
few isolated antennas designed to act as gateways to the internet.

Of course, the handsets would differ from the usual cellular handset in that
it would be able to forward packets for other users and might also be
strictly digital, with limited digital voice, to compensate for the limited
bandwidth.

The question is, how will a user entering the region of a local MANET be
properly identified and make its location known to other hosts, including
those access through the Internet.

My thought is this:

Suppose there were on the Internet a number of special servers whose
function is to provide directory service for this class of users.  Each
mobile host would have a unique identifier (IP?) that would be easily
associated with a subset of these servers, much like area code gives us an
idea of what state the user is in.  However, this is just to simplify the
task of finding an entry and has nothing to do with the host's current
association or location.

Whenever a host comes within range of one of the associated MANETs, it
recognizes, through Hello messages, the proximity of like hosts and
broadcasts its own request to join.  Once the local group accepts its
membership, it unicasts a location packet to one of the Internet gateways,
which keeps this information for its own use, but also forwards to the
appropriate directory server the host's IP as well as the gateway's own IP.
Then, any host accessing through the Internet, trying to find the mobile
host in question, would request directory assistance, finding whatever
information it needs to route packets to the gateway.

Technically, I realize, this is a form of centralized information storage,
but it is for the purpose of locating a particular host that may be on any
one of hundreds of MANETs, or on none.  The storage is on the Internet, not
on the MANET.  Local MANET routing information would not be forwarded, so
the directory entry would be valid (and useful) as long as the host is in
that particular MANET, even if the route to it within the MANET changes. 

John Mullen

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From: "Phil Neumiller" <[email-masked]>
Date: Wed, 10 Jul 2002 10:13:18 -0400

Hi John,

> few isolated antennas designed to act as gateways to the internet.

Check out www.meshnetworks.com.  We have built this system.  We call our
gateways, Intelligent Access Points (IAPs).

> those access through the Internet.

What we do, is allow the MANET algorithm to extend to the IAPs.  The
IAPs can route anyway they want on the backside.  This bridges our MANETs
with the global Internet quite nicely.

> task of finding an entry and has nothing to do with the host's current

I don't think you really need any kind of special server, unless its a 
Mobile IP agent!!!  Mobile IP does what your suggesting here quite
nicely BTW.

> information it needs to route packets to the gateway.

All it has to do is do a MIP handover between the MANETs.

> that particular MANET, even if the route to it within the MANET changes. 

MIP agents don't have to be centralized, except for the home agent that can
be easily be made redundant, i.e. the only stateful host.  The FA is eliminated
in IPv6 with colocated COA.

You are mulling something that has been done for quite some time by MIP!

Thanks,

Phil

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From: "Phil Neumiller" <[email-masked]>
Date: Wed, 10 Jul 2002 10:13:18 -0400

Hi John,

Thanks,

Phil