Subject: Re: [rrg] Summary of architectural solution space

From: [email-masked]
Date: Sun, 21 Dec 2008 11:17:03 EST

In einer eMail vom 21.12.2008 15:38:19 Westeuropäische Normalzeit schreibt  
[email-masked]:

I  think that the real problem is that with current techniques, there
is a  serious mismatch between the number (millions or in the future,
perhaps  hundreds of millions or billions) of end-user networks which
want  multihoming, TE and/or portability and the only way this can
currently be  provided - by globally routed prefixes for every such
end-user network,  which every DFZ router needs to handle in its RIB
and generally in its  FIB.
My saying since 45. I have referred to two other networks which both are  
1000 times larger:
the road network, and the postal service network. None of them has this  
crazy problem because none of them does user reachability information  
dissemination. Let me point to a 3rd network: the railroad network.
There a single link (=railway between two distant cities) may take 10 years  
building it. So there is, broken down to a single second, in principle zero  
change. But if you assume 6 billion people on earth and each of them may move  
every ten years to another location, and if you disseminated their individual  
change of address information to all railway stations you will create a  
considerable update churn. 
 
Isn't  it very obvious that this concept is absurd ?
 
And that the scalability problem is NOT due to expressing three different  
concepts, as is stated?

It is  not open to us to say the problem lies in millions of end-user 
networks  wanting multihoming, TE and/or portability.  So the problem
is that  the current architecture can't scale to meet this demand.

That is the  guts of the problem.  It is only one interpretation of
the problem to  see it in terms of IP addresses being used for too
many purposes all at  once, which is your page's current definition of
the root cause of the  scaling problem.

There are potential host-based solutions - with new protocols  and
changes to stacks and applications - which pushes the  responsibility
for multihoming, TE and portability to each host, by way  of
separating out the various functions into physically  separate
entities, such as for GUID, SID and LOC.  But that doesn't  mean the
only or best definition of the problem is in these  terms.

Such a solution necessarily involves every host in fussing  around
with changes in the core of the Net.  I see many problems with  this:

Fundamental objections to a host-based scalable routing  solution
_http://www.irtf.org/pipermail/rrg/2008-November/000271.html_ 
(http://www.irtf.org/pipermail/rrg/2008-November/000271.html) 

Routing is first of all a network issue, but this should not prevent that  
hosts can take influence on routing wrt their sent/ sent-to packets. Why EITHER  
- OR ? Why not enable BOTH ? TARA requires such little data, that multi-homed 
 users could -technically- get them from each adapted ISP. Politically, is a  
different story.
 
A further note about "steal of service/ discriminating routing / internet  
economic model":
I have my doubts that the current internet economic model enables that a  
transit network in the middle (and not at the ends) of some path can  
discriminate the packet flow just as well as when being at its end.
It seems to me that a special aspect is picked  for argumenting  against 
strategies B and C.
 
Another note concerning strategy B: It looks like PNNI, which I do know  very 
well, which I once supported very much, which I tried to emulate at the  
beginning of NIRA, too, but which does topology aggregation in a wrong  way.  
 
Heiner 

_______________________________________________
rrg mailing list
[email-masked]
https://www.irtf.org/mailman/listinfo/rrg

---

From: "William Herrin" <[email-masked]>
Date: Sun, 21 Dec 2008 17:57:28 -0500

On Sun, Dec 21, 2008 at 11:17 AM,  <[email-masked]> wrote:
> building it.

Heiner,

How do you select which train or flight you will take?

When I select a train or flight, I have multiple considerations:

1. From the potentially viable destination stations, how convenient is
the street-level route I've precomputed after acquiring a local map?
If I take a cab, how much will the cab fare cost? Would it be cheaper
to rent a car?

2. From the potentially viable source stations, how convenient is the
street-level route from my current location? If I take a cab, how much
will the cab fare cost? Would it be cheaper to pay for parking at the
station?

3. Which trains or flights go to the stations in question during the
period I want to travel?

4. Which train or flight is offered at a price I'm willing to pay?

You'll notice that in order to take a single long trip, I've acquired
a substantial subset of the routing data and applied a very complex
set of heuristics in order to precompute my door-to-door route.

And did I mention that the trains and aitlines are regularly bankrupt?
It seems they have a helluva time managing their costs.

Geographic routing for human travel may seem simple and efficient, but
it only seems that way.

Regards,
Bill Herrin

-- 
William D. Herrin ................ [email-masked]  [email-masked]
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004
_______________________________________________
rrg mailing list
[email-masked]
https://www.irtf.org/mailman/listinfo/rrg