Subject: RE: [nemo] Announcing the Global HAHA draft

From: "Dul, Andrew L" <[email-masked]>
Date: Fri, 3 Dec 2004 14:32:07 -0800

> -----Original Message-----
> From: Ryuji Wakikawa [mailto:[email-masked]]
> Sent: Wednesday, November 17, 2004 10:44 PM
> At Wed, 17 Nov 2004 08:34:29 -0800,
> Dul, Andrew L wrote:
> >
> > I think one of the reasons why you haven't seen a lot of
> interest on
> > this draft is that the truly global mobility market is really very
> > small.  The aircraft industry also tends to move quite slow 
> compared
> > with the speed of technology & adoption in the "Internet"
> space.  When
> > I think about the objects that are really truly globally mobile in
> > most cases they are limited to aircraft, maritime vessels, 
> & people.
> > Even when you think about people further, we are mostly regionally
> > mobile. Sure we travel to different parts of the globe but 
> most of us
> > are generally only regionally mobile, and when we are
> outside of our
> > normal region we are often there for only shorter periods of time.
> > Jet aircraft are somewhat unique in that they can traverse 
> the entire
> > globe within a single day.
> 
> The airplane is perfectly applicable scenario. There are
> also useful cases without globally physical movements.
> For example, automobile industry is also interested in this
> topic. When considering Europe automobile market, where can 
> they put HA? 1 HA for each country? Commercial tracks often 
> drive beyond countries. If I got Japanese car in Europe, MNP 
> might be configured with the home network in Japan.  

I would expect for an automobile that the HA would be associated with
the service provider that is providing the connectivity service for the
automobile.  For example if I bought an Japanese car and it is sold &
used in Europe, the connectivity service would be provided by a company
with service in Europe.  This is not to say that the service provider
couldn't be based somewhere else and have the HA outside of Europe but
my guess is that these types of service providers will be regionally
based.  I consider an automobile to be generally regionally mobile, not
globally mobile.

> 
> > As I read through the draft (4.1.1.) I can see areas where the
> > tunneling in a global environment can still cause a large 
> increase in
> > latency. Consider the following case.  Service provider A
> has a ground
> > global-haha network that an aircraft attach to in London &
> Sydney, in
> > this case the aircraft is owned by company Z with
> operations in Chicago
> > served by Service provider B.   The plane is on the ground 
> in Sydney and
> > maintenance staff are using the onboard IP phone to talk to
> operations
> > staff in Chicago.   Given a set of BGP routing tables it is possible
> > that the path through the London HA would be a perceived best path
> > from Chicago.  In this case the call would be routed from 
> Chicago to
> > London to Sydney instead of directly to Sydney.  In the v4 world we
> > have used a BGP rehoming solution that can largely negate 
> this issue.
> > At this point it is unclear to me if a similar rehoming solution is
> > possible or desirable in the multihomed v6 world.  This also may be 
> > too much of a corner case but it is nonetheless an interesting case.
> 
> Isn't it possible that service provider B joins the
> global-haha network of service provider A?  And if service 
> provider A advertise the same prefix from London and Sydney 
> to BGP, operator in Chicago should pick the path via Sydney 
> (when IP distance is really shorter).
> 

This could be possible.  The real question is if there will be
"global-haha peering" between a majority of the service providers.  If
there are only a few service providers who support this feature then it
is not as useful, IMO.  Protocols like RSVP come to mind...good ideas,
but they aren't very useful if everyone doesn't support it.

> > In my opinion I believe that for a global mobility standard to be 
> > truly successful it must allow for the mobile networks to 
> roam between 
> > service providers & BGP ASNs.  This aspect brings up 
> another whole set 
> > of issues with address allocation, v6 multi-homing, and 
> integration with BGP.
> > (Which maybe outside the scope of the NEMO charter?)   I 
> also note that
> > many of these issues are still not finalized in the v6 
> world from my 
> > current readings.  Authentication & Authorization for MR's 
> to the mesh 
> > between ASNs is also a consideration.  As Terry Davis one of my 
> > colleagues stated in a previous mail, it is likely that the 
> aircraft 
> > networks will be connected to a number of other networks 
> via different 
> > mechanisms, some of them will be satellite based, some 
> air-to-ground, 
> > and some ground-to-ground when the aircraft is between flights. 
> > Specifically for the ground-to-ground links it is unlikely that a 
> > single service provider would be able to provide global coverage at 
> > any large majority of world airports.
> 
> Global-HAHA enables full HA operations on IP layer.  It means 
> we can put HAs over ASN if each HA advertise the same home 
> network prefix by BGP. It might be possible to see some super 
> ISP beyond ASN for globally mobility in near future:-)
> 

While this is all possible, the question remains if it will be
practical, in the real world of network operations.  Lots of tunneling
also tends to make connectivity problems harder to pinpoint &
troubleshoot (I'm personally not a big fan of tunneling)   If I am
service provider A, I may not want one of my competitors "B" announcing
address space for someone who is generally a customer service provider
A.  There are also lots of security issues when "anyone" could announce
the space.  How do you know if the prefix being announced is legitimate?
Also how do you assign the address space?  

To make this even reasonable you would have to have a separate address
block that only contained mobile platforms.  To me this makes the most
sense.  If we really want to prevent huge growth in the DFZ separate
large aggregate blocks for mobile networks will be required.  Agreements
to exchange mobile network routes will have to be created between
Service Providers.  In the end, if only a few providers exchange the
mobile routes then we lose the ability to have globally optimized
routing.  Perhaps we want to consider treating the mobility of "large
networks" like planes, ships, etc differently than "small networks" like
phones & PDAs.  There are probably a couple orders of magnitude
difference between the number of "small" vs "large" networks.  Maybe
they need different types of optimization and mobility protocols.

Andrew