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Re: Converged Networks Threat (Was: Level3 Outage)

  • From: vijay gill
  • Date: Thu Feb 26 13:14:36 2004

On Thu, Feb 26, 2004 at 10:05:03AM -0800, David Barak wrote:
> 
> --- vijay gill <vgill@vijaygill.com> wrote:
> > How would you know this?  Historically, the cutting
> > edge technology
> > has always gone into the large cores first because
> > they are the
> > ones pushing the bleeding edge in terms of capacity,
> > power, and
> > routing.
> > 
> > /vijay
> 
> I'm not sure that I'd agree with that statement: most
> of the large providers with whom I'm familiar tend to
> be relatively conservative with regard to new
> technology deployments, for a couple of reasons:
> 
> 1) their backbones currently "work" - changing them
> into something which may or may not "work better" is a
> non-trivial operation, and risks the network.

This is perhaps current. Check back to see large deployments
GSR - sprint/UUNEt
GRF - uunet
Juniper - UUNET/CWUSA

In all of the above cases, those were the large isps that forced
development of the boxes. Most of the smaller "cutting edge"
networks are still running 7513s.

GSR was invented because the 7513s were running out of PPS.
CEF was designed to support offloading the RP.

> 2) they have an installed base of customers who are
> living with existing functionality - this goes back to
> reason 1 - unless there is money to be made, nobody
> wants to deploy anything.
> 
> 3) It makes more sense to deploy a new box at the
> edge, and eventually permit it to migrate to the core
> after it's been thoroughly proven - the IP model has
> features living on the edges of the network, while
> capacity lives in the core.  If you have 3 high-cap
> boxes in the core, it's probably easier to add a
> fourth than it is to rip the three out and replace
> them with two higher-cap boxes.

The core has expanded to the edge, not the other way around.
The aggregate backplane bandwidth requirements tend to
drive core box evolution first while the edge box normally
has to deal with high touch features and port multiplexing.
These of course are becoming more and more specialized over
time.

> 4) existing management infrastructure permits the
> management of existing boxes - it's easier to deploy
> an all-new network than it is to upgrade from one
> technology/platform to another.

Only if you are willing to write off your entire capital
investment. No one is willing to do that today.


> 
> -David Barak
> -Fully RFC 1925 Compliant
> 


/vijay
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