Re: [Bloat] Random idea in reaction to all the discussion of TCP flavours - timestamps?

[Jonathan Morton <chromatix99@gmail.com>]

On 16 Mar, 2011, at 3:59 am, Dave Täht wrote:

> 10 Gig E - 10Gig Switch to 1Gig
>           | | | | | | | | | |
>           1 2 3 4 5 6 7 8 9 0 
> 
> And the server connected servicing hundreds of flows. Statistically,
> with fair queuing the number of receive buffers required per port will
> be close to or equal to 1, where in a primitive FIFO setup, something >
> 10 are required.

Well, that's a rather different picture than I had before.  I'd hazard a guess that most good switches can deal with that, but they are switches, not routers, so latency through them is expected to be even less.

With that said, at 10GE speeds you are approaching a megapacket per second if jumbo frames are not a significant fraction of the traffic.  I think something like SFQ can be made to work at those speeds, but simply getting the data through the computer that fast is a fairly tough job.  So I agree that if the NIC can do it by itself, so much the better.

On the flip side, at a megapacket per second, a thousand-packet buffer empties in a millisecond.  That's less than a disk seek.

 - Jonathan