--- vijay gill <[EMAIL PROTECTED]> wrote:
> 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. > Hmm - what I was getting at was that the big ISPs for the most part still have a whole lot of 7513s running around (figuratively), while if I were building a new network from the ground up, I'd be unlikely to use them. > 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. > I agree, from a capacity perspective: the GSR began life as a core router because it supported big pipes. It's only recently that it's had anywhere near the number of features which the 7500 has (and there are still a whole lot of specialized features which it doesn't have). From a feature deployment approach, new boxes come in at the edge (think of the deployment of the 7500 itself: it was an IP front-end for ATM networks) > > 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. That is EXACTLY my point: as new companies are unwilling to write off an investment, they MUST keep supporting the old stuff. once they're supporting the old stuff of vendor X, that provides an incentive to get more new stuff from vendor X, if the management platform is the same. For instance, if I've got a Marconi ATM network, I'm unlikely to buy new Cisco ATM gear, unless I'm either building a parallel network, or am looking for an edge front-end to offer new features. However, if I were building a new ATM network today, I would do a bake-off between the vendors and see which one met my needs best. -David Barak -Fully RFC 1925 Compliant- ===== David Barak -fully RFC 1925 compliant- __________________________________ Do you Yahoo!? Get better spam protection with Yahoo! Mail. http://antispam.yahoo.com/tools
