BCP for multisite multihoming

[Jason Schiller]

On Tue, 22 May 2007, Thomas Narten wrote:

> Iljitsch van Beijnum <iljitsch at muada.com> writes:
> 
> > On 21-mei-2007, at 23:43, David Conrad wrote:
> 
> > >> At this point, I guess it's time to once again point out that all  
> > >> of this could be avoided if the IETF would simply overcome its  
> > >> irrational fear of geography-related routing: http://www.muada.com/ 
> > >> drafts/draft-van-beijnum-multi6-isp-int-aggr-01.txt
> 
> > > The IETF is mostly irrelevant in this context.  The folks who have  
> > > to get over their fear (irrational or not) is the Internet service  
> > > provider community.
> 
> > The trouble is, for this to work without too much trouble, address  
> > space needs to be given out with geography in mind. I don't think  
> > IANA and the RIRs are going to do that without the IETF telling them  
> > it's a good idea.
>
> David said it already. The IETF won't waste it's time doing this so
> long as it thinks that the proposal will go nowhere in
> practice. Presumably, we all have better things to do with our time.
>
> Thomas
>

I concur.  The problem with a geography-related approach to routing, is
that all of the ISP networks also need to be reorganized to also be
related to the geography.  As Yakov Rekhter says architecture can follow
addressing or addressing can follow architecture.  This is a very
expensive proposition.

Routers may be required to be added to enforce routing policy at all
geographical boundries.  Links may be required for all locations with a
given geographical region to be able reach each other without traversing
another geographical region.

In short all transit providers will need to restructure their networks to
mirror the geographical regions.  This may be contrary to the best
business decesions.  If one or more transit providers uses arbatrary
geographical regions, then it/they can game the system and make them
selves more prefered to multi-homed destinations by sources in region by
over sizing the region, or more prefered to multi-homed destinations in
the region to sources out of region by undersizing the region.  

All transit providers in a given geographical region would be required to
do SFI-Peering, or small transit providers will be forced to buy transit
from all large transit providers, or work out some sort of paid peering
arragnement with all large transit providers (assuming the small transit
providers would simply do SFI-Peering).

Peers should only excnage local geographical region routes at a Peering
point within the geographical region.  The number of Peering points wold
be equal to the number of geographical regions were the provider sells
service.  If a Peering point in a single region goes down, then customer
in that region will not be reachable though another Peering point in
another region.  Thus multiple Peering points may be required in each
region to allow for either fail-over or the ability to move traffic
away from congested links.

It is not clear what the approprate geographical region is-- should it be
per continent? per country? per metro area of a give sized
polulation? per area code? per city? per LATA? per zip code designation? 
per sub-development? per street? per city block? per building? per floor?

Do you give each geographical region the same amount of IP space?  What if
a region consists entirely of desert or ocean? Should it be based on
population density?

It is likely that this can only occur if governments set geographical
regions and force transit providers to structure their networks as such,
and regulate all Peering. This sort of legal requirements are not likely
to produce optimal, cheap, or sain networks.

__Jason