RE: remember the "diameter of the internet"?

["Martin, Christian" <cmartin () gnilink net>]

> > 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 :)

Router hardware can be pretty flaky as well... ;)

I was more referring to the nature of IP.  With the exception of IS-IS, all
IP control plane protocols are subject to abuse/attack by the same data
plane that they are intending to control.

> > 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.

Ouch.

> > 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. 

There are opponents to this assertion.  I haven't seen enough of what's in
the sausage to make a firm statement either way.  What I do know is that the
class-5 switch is designed to save lives.  A router is designed to fill
vendor wallets.  That, coupled with experience in the field suggests,
coupled with dogma and the high-level of sensitivty to being burned
repeatedly, suggests that the trend for chassis redundancy requiring massive
amounts of wasted space, unnecessary hierarchy, and added complexity to
continue.  Ces't la Vie!

> 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.

Yep!

-chris


> --vadim