[48908] in North American Network Operators' Group
RE: remember the "diameter of the internet"?
daemon@ATHENA.MIT.EDU (Martin, Christian)
Wed Jun 19 13:45:14 2002
From: "Martin, Christian" <cmartin@gnilink.net>
To: nanog@merit.edu
Date: Wed, 19 Jun 2002 13:44:38 -0400
Errors-To: owner-nanog-outgoing@merit.edu
>> 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
>
