RE: remember the "diameter of the internet"?

[Vadim Antonov <avg () exigengroup com>]

On Tue, 18 Jun 2002, Martin, Christian wrote:

> > Regarding the diameter of the Internet - I'm still trying to 
> > figure out 
> > why the hell anyone would want to have "edge" routers (instead of dumb 
> > TDMs) if not for inability of IOS to support large numbers of virtual 
> > interfaces.  Same story goes for "clusters" of backbone routers.
>
> When ANY router becomes as reliable as a dumb TDM device, then maybe we can
> begin collapsing the POP topology.  However, the very nature of the Internet
> almost prevents this reliability from being achieved (having a shared
> control and data plane seems to be the primary culprit).

Uhm. Actually, control & data planes are rather separate inside modern
routers. What is flaky is router software.  That's what you get when your
router vendor sells you 1001 way of screwing up your routing :)

> There are routers out there today that can single-handedly replace
> entire POPs at a fraction of the rack, power, and operational cost.  
> Hasn't happened, tho.

I know two boxes like that - one is broken-as-designed, with copper 
distributed fabric; another (courtesy of VCs who managed to lose nearly 
entire engineering team mid-way but hired a bunch of marketers long before 
there was anything to ship) is still in beta.

> I don't like wasting ports for redundant n^2 or log(n^2) interconnect
> either, but router and reliability mix like oil and water...

Actually, not.  A router is a hell of a lot simpler than a Class-5 switch, 
particularly if you don't do ATM, FR, X.25, MPLS, QoS, multicast, IPv6, 
blah, blah, blah. 

Demonstrably (proof by existence), those switches can be made reasonably
reliable. So can be routers. It's the fabled computer tech culture of "be
crappy, ship fast, pile features sky high, test after you ship" aka OFRV's
Micro$oft envy, which is the root evil.

--vadim