Re: Send-n, rat holes and real issues

At 22:13 +1000 7/7/08, Duane wrote:
>Otmar Lendl wrote:

Otmar made some good observations.

>>  We (including speermint) have been though that discussion already
>>  a few times. A BGP-like protocol for numbers (or better: prefixes)
>>  just won't scale.
>
>Why would DNS scale any better?

DNS scales larger than BGP in the sense that the data held by DNS 
does not travel like the data held by BGP.  Let's say you have 
10,000,000 phone numbers with number portability.

In DNS I would need to have 10,000,000 NAPTR sets residing in a 
handful of servers (all under my administrative control) in key 
places.

In BGP, without aggregation, I would have to see that 10,000,000 
route entries would have to be sent to all of the routing points 
globally, not all under my control.

That's the idea in a nutshell - DNS does not attempt to move the data 
model everywhere, BGP does.  (Note - this is not a stab at BGP, the 
jobs of the two protocols are different.)

>>  One part of what makes BGP work for IP routing is the aggregation
>>  properties of IP addresses: large blocks are given to ISPs, which give
>>  out smaller blocks to enterprises, or just individual addresses to
>>  end-users.
>
>Lets be clear here, we're not talking about routing, just prefixes and
>there is a HUGE difference because there is much less problems with
>security implications at the very least.

I think the point Otmar is making is that when you look at a IPv4 
address, the first N bits determine where all the 32-N bit addresses 
are.  I.e., a 10.10.10/24 route (if none are more specific) will be 
the path for all 256 numbers in 10.10.10.0-255.  But for +1-571-555, 
not all 10,000 below what will be routed the same way.

The obsevation of Otmar that I think is great is that telephone 
numbers, when backed by number portability, are no longer network 
addresses but are network names.  Yet, an IP address is just an 
address, not a name.  A lookup service (like DNS) or a 
directory/database deals with names better than addresses, a routing 
service deals with addresses better than names.

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Edward Lewis                                                +1-571-434-5468
NeuStar

Never confuse activity with progress.  Activity pays more.