On Thu, Dec 11, 2008 at 5:50 PM,  <[email protected]> wrote:
> In einer eMail vom 11.12.2008 23:11:52 Westeuropäische Normalzeit schreibt
> [email protected]:
>> As I mentioned in our email exchange, I don't understand what this
>> means. What is a "well-sparsed" Internet?
>
> A topology which doesn't show the details of the remote  network parts.
> Similar to routing from NY, Broadway to Sausolito, Main Street without
> seeing the Main-Street prior entering Sausilito itself.

Hi Heiner,

I think I'm going to stick with "aggregated." You've aggregated
Broadway into New York and you've aggregated Main Street into
Sausolito. Unless there is some subtlety to the notion of "well
sparsed" that you haven't communicated?

"Well sparsed" has no meaning in network engineering that I'm aware
of. The only time I recall encountering the word "sparse" in network
engineering was in describing an address assignment strategy where new
assignments try to split the largest available free space so that they
have the the best probability of being later growable by only changing
the netmask.


> > What is a loose or strict link?
>
> This is IETF terminology.

I haven't heard it before and I still don't know what you're talking about.

Did you mean to say loose-source-route like what Anja presented in the
HAIR documents? I could see that as a variant C2:

C2. Replace the endpoint's IP address with a loose source route and
update protocols accordingly. The loose source route consists of a
sequence of waypoint addresses, the first of which is expected to be
known to all routers on the Internet and the last of which is the
destination machine. Each waypoint router is required to know a route
to at least one of the later waypoints or the final destination.

Reminds me of my old UUCP email address...

One interesting consequence of C2 is that you get an effectively
variable-length address while each router that isn't a waypoint only
needs to consider a fixed length address. No more worries about
running out of addresses; you just place non-unique addresses behind
another waypoint.

Something similar to C2 would probably also be legitimate for strategy
B, where a link failure causes you to replace one of your waypoints
but leaves the rest alone instead of completely changing your locator.


>> How do you determine that a node is "closest to" a node that
>> isn't visible?
>
> By the distance (in miles or km) which is adequate in location base routing - 
> IMO.

How do you know the distance if information about the node isn't
visible? Is it encoded in the network address? How?


>> What is the significance of 1 or 3 table lookups?
>
> Much faster forwarding. Eliminating the need for caching.

Let me try again: You've made a leap in logic from loose and strict
links to 1 or 3 table lookups. Please fill in the middle.


> I have one further comment with respect to the mentioned economic model of
> IP. It is just the opposite:
> Strategy C avoids everything which looks like administrative hierarchy.
> Rather ask ILNP or HAIR or Joel's presentation. There is no single hint for
> any political/administrative influence in all of what I presented.

That's the criticism, that administrative routing policy is a
mission-critical feature of any routing protocol and strategy C fails
to support it. Authors of strategy C systems should expect to be asked
how their approach avoids the theft-of-service problem. If they wish
to be taken seriously, those authors should prepare a thorough and
well-considered answer.

Regards,
Bill Herrin



-- 
William D. Herrin ................ [email protected]  [email protected]
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004
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