On Sat, Mar 12, 2011 at 2:17 AM, Joel Jaeggli <joelja@bogus.com> wrote:
I'm super-tired of the "but tcams are an expensive non-commodity part not subject to economies of scale". this has been repeated ad nauseam since the raws workshop if not before.
You don't have to build a lookup engine around a tcam and in fact you can use less power doing so even though you need more silicon to achieve increased parallelism.
Hi Joel, You're either building a bunch of big TCAMs or a radix trie engine with sufficient parallelism to get the same aggregate lookup rate. If there's a materially different 3rd way to build a FIB, one that works at least as well, feel free to educate me. And while RIB churn doesn't grow in lockstep with table size, it does grow. Either way when you boost from 1M to 10M you're talking about engineering challenges with heat dissipation and operating challenges with power consumption, not to mention more transistors. I'll be convinced it can be done for less than 2x cost when someone actually does it for less than 2x cost. Whether it's 2x cost or 1.2x cost, the point remains the same: we could have routers today that handle the terminal size of the IPv4 table without breaking the bank. Your favorite router manufacturer has made vague assertions about how they would build one given sufficient customer demand. So make a demand. Regards, Bill Herrin -- William D. Herrin ................ herrin@dirtside.com bill@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004