[ih] IP addresses are not phone numbers, was Some Questions over IPv4 Ownership

[Miles Fidelman]

Scott Brim wrote:
> On 10/17/2010 17:58 PDT, Miles Fidelman wrote:
>    
>> Well... for current software to work right, maintaining a TCP connection
>> requires that the underlying IP addresses remain the same (at least I
>> think it does).  So somehow the IP numbers have to stay the same, while
>> the underlying network connection changes.
>>
>> It's not necessarily a link-layer function to do the handoff, but what
>> is actually changing is happening at the link layer - one physical link
>> is dropping, and a new one is coming up.
>>
>> The hand-off is really a routing function - changing the mapping between
>> a specific IP address and a specific physical link.  That shouldn't be
>> too hard to do if one carrier is handing things from one asset to
>> another, seems a bit more difficult when two carriers are involved - and
>> brings us back to the original question of who "owns" the IP address
>> when more than one carrier is involved. :-)
>>      
> Got it.  You're trying to work with current software.  That can be done
> below the L3/L4 monolith, or above it (in the app layer) and of course
> we're trying to break the monolith apart.  Every mechanism has areas
> where it's useful.
>    
I've always been a big fan of layering - it's been instrumental in 
enabling the rather rapid evolution we've seen at all layers of the 
Internet.  I expect that we'll make more progress by localizing changes 
in ways that don't break the layers that work, and don't need to 
change.  I'd really hate to see anything that resembles the (IMHO) 
abortion we see in W3C-style web services, where all kinds of lower 
layer functions have been pushed to somewhere above HTTP.

Cheers,

Miles

-- 
In theory, there is no difference between theory and practice.
In<fnord>  practice, there is.   .... Yogi Berra