On Mon, May 08, 2000 at 08:59:23AM -0700, Greywolf wrote:
> On 8 May 2000, Perry E. Metzger wrote:
> 
> # Greywolf <greywolf@starwolf.com> writes:
> 
> 1.  Do ATM or ISO OSI attempt to deal with the limited address space in
>     which we currently live?
One of the original candidates for IPv6 was TUBA; a slightly modified
OSI protocol stack. If memory doesn't fail me, it was actually decided
on by the IAB without involving the community at large (i.e. IETF).
The resulting outrage at this decision resulted in a re-organization
of the IAB and the decision process. The decision was rolled-back and
it was left to the IETF community to discuss the alternatives for an
IPng. TUBA was an important candidate for a long time, although its
main assets were political/philosophical I think rather than
technical. 

It did deal with the limited address space as addresses are
20 bytes octets there (so even bigger than in current IPv6) and in
theory at least could be even variable length. ATM is a different
story as IMHO it is more of `just another link layer protocol'
(although some would say: a very nifty, intelligent, or just very
complex one) than  a protocol for global internetworking. 

The great asset of IPv6 is that it builds upon the extensive
experience gained with IPv4. IPv4 is the only protocol in use today 
that has proven itself on a global scale of internetworking. It just 
has some limitations and experience has shown what features of IPv4 
didn't work out in practice. 

The strength and beauty of IPv6 is that it is just
a redesign (evolution in a way) of IPv4, without being a patched up
version of it. Essentially IPv6 is a stripped version of IPv4 that
uses bigger addresses. Second, with IPv6 an attempt is made to change
the way packet routing is performed and addresses are structured in
order to make routing on defaultless backbone routers much more
simpler (by building a hierarchical addressing structure). This is 
not inherent to IPv6 (it merely facilitates it), although it is 
currently the only addressing architecture designed and implemented, 
if experience or need dictates other addressing architecture could be
added. 

In addition it has been designed such that
new functionality is easy to add without having to fall back to ugly
hacks necessary in IPv4 (like autoconfiguration, mobile IP, IPSEC, intserv 
and diffserv stuff etc...). These things have little to do with IPv6
itself. IPv6 makes researching, developing and implementing such
extensions just a lot easier and nicer.
 
> 2.  Are we not running the ISO stack in networking right now?  I thought
>     the "old" TCP/IP stack had already been phased out (I can hear it
>     already:  "Gods, NO!  Where have you been?").  Never mind :-)
I think not. What survived of OSI/RM is the terminology and ..., and
..., and....... (well, just fill in what you can think on the dots. Don't
flame me for having no clue what else to add there ;)

> I think I may win that bet.
I think so too ;)

Feico.