On 8/13/07, Leo Bicknell <[EMAIL PROTECTED]> wrote: > In a message written on Mon, Aug 13, 2007 at 02:29:14PM +0200, Eliot Lear > wrote: > > This assumes "the real problem" is CPU performance, where many have > > argued that the real problem is memory bandwidth. Memory doesn't track > > Moore's Law. Besides, Moore's Law isn't a law. What's your Plan B? > > This is where a lot of RRG/RAM work is going on right now. > > I think there are multiple problems with core routers. However, > the discussion here was about BGP being able to converge. For that, > the FIB is not important, there need be no routing plane. > > What sort of computer does it take to get 200 sessions at an exchange > point and compute a FIB in a "reasonable" amount of time? That's > determined first by the implementation (algorithm) and second by > the processor speed. It may also be impacted due to the bandwidth > between routers, although I'm skeptical that's an issue. > > [Why? Let's say 10,000 routes per peer, and 50 peers all on a single > giabit ethernet exchange. Let's also put an upper bound of 512 bytes > per route. That's ~250Mbytes, or what, maybe 30 seconds?] > > It seems to me an off the shelf PC with a Core 2 Duo processor, 4 > gig of memory, and a gigabit ethernet port would be 1-2 orders of > magnitude faster than what's currently in the routers. Optimize > for a multithreaded CPU, add a second and it would converge really > fast. My own experience is that zebra / quagga blow away the > performance of any router out there as long as you don't ask them > to install the routes in the kernel (which is really slow in a > general purpose OS).
Pick a newly released Core 2 Duo. How long will Intel be selling it? How does that compare with getting it into your RP design, tested, produced, OS support integrated, sold, and stocked in your depots? -Scott > > Now, once the FIB is computed, can we push it into line cards, is > there enough memory on them, can they do wire rate lookups, etc are > all good questions and all quickly drift into specialized hardware. > There are no easy answers at that step... > > -- > Leo Bicknell - [EMAIL PROTECTED] - CCIE 3440 > PGP keys at http://www.ufp.org/~bicknell/ > Read TMBG List - [EMAIL PROTECTED], www.tmbg.org > >
