nanog mailing list archives
Re: 10GE TOR port buffers (was Re: 10G switch recommendaton)
From: Joel jaeggli <joelja () bogus com>
Date: Fri, 27 Jan 2012 16:00:36 -0800
On 1/27/12 15:40 , bas wrote:
Hi All, On Sat, Jan 28, 2012 at 12:32 AM, Joel jaeggli <joelja () bogus com> wrote:On 1/27/12 14:53 , bas wrote:While I agree _again_!!!!! It does not explain why TOR boxes have little buffers and chassis box have many.....you need purportionally more buffer when you need to drain 16 x 10 gig into 4 x 10Gig then when you're trying to drain 10Gb/s into 2 x 1Gb/s there's a big incentive bom wise to not use offchip dram buffer in a merchant silicon single chip switch vs something that's more complex.I'm almost ready to throw the towel in the ring, and declare myself a looney.. I can imagine at least one vendor ingnoring the extra BOM capex, and simpky try to please #$%^#@! like me. C NSP has been full with threads about appalling microburst performance of the 6500 for years..
And people who care have been using something other than a c6500 for years. it's a 15 year old architecture, and it's had a pretty good run, but it's 2012. An ex8200 has 512MB per port on non-oversuscribed 10Gig ports and 42MB per port on 1Gig ports. that's a lot of ram. to take this back to actual tors. a broadcom 56840 based switch has something in the neighborhood of 9MB available for packet buffer on chip if you need more then more drams are in order. while the TOR can cut-through-switch the chassis can't. the tor is also probably not built with offchip cam (there are examples of off chip cam as well) for much the same reason.
One would think a vendor would jump to a copetitive edge like this...
Current thread:
- Re: 10GE TOR port buffers (was Re: 10G switch recommendaton), (continued)
- Re: 10GE TOR port buffers (was Re: 10G switch recommendaton) Nick Hilliard (Jan 27)
- RE: 10GE TOR port buffers (was Re: 10G switch recommendaton) George Bonser (Jan 27)
- RE: 10GE TOR port buffers (was Re: 10G switch recommendaton) George Bonser (Jan 27)
- Re: 10GE TOR port buffers (was Re: 10G switch recommendaton) bas (Jan 27)
- RE: 10GE TOR port buffers (was Re: 10G switch recommendaton) George Bonser (Jan 27)
- Re: 10GE TOR port buffers (was Re: 10G switch recommendaton) bas (Jan 27)
- Re: 10GE TOR port buffers (was Re: 10G switch recommendaton) Joel jaeggli (Jan 27)
- RE: 10GE TOR port buffers (was Re: 10G switch recommendaton) George Bonser (Jan 27)
- Re: 10GE TOR port buffers (was Re: 10G switch recommendaton) Joel jaeggli (Jan 27)
- Re: 10GE TOR port buffers (was Re: 10G switch recommendaton) bas (Jan 27)
- Re: 10GE TOR port buffers (was Re: 10G switch recommendaton) Joel jaeggli (Jan 27)
- pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) Randy Bush (Jan 27)
- Re: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) Leo Bicknell (Jan 27)
- Re: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) Randy Bush (Jan 27)
- Re: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) Leo Bicknell (Jan 27)
- Re: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) Randy Bush (Jan 27)
- Re: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) Leo Bicknell (Jan 27)
- Re: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) Leo Bicknell (Jan 27)
- RE: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) George Bonser (Jan 27)
- Re: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) Jared Mauch (Jan 29)
- RE: pontification bloat (was 10GE TOR port buffers (was Re: 10G switch recommendaton)) George Bonser (Jan 29)