10GE TOR port buffers (was Re: 10G switch recommendaton)

bas kilobit at gmail.com
Fri Jan 27 16:30:14 CST 2012


Hi,

On Fri, Jan 27, 2012 at 10:52 PM, Leo Bicknell <bicknell at ufp.org> wrote:
> In a message written on Fri, Jan 27, 2012 at 10:40:03PM +0100, bas wrote:
>> But do you generally agree that "the market" has a requirement for a
>> deep-buffer TOR switch?
>>
>> Or am I crazy for thinking that my customers need such a solution?
>
> You're crazy. :)
>
> You need to google "bufferbloat", which while the aim has been more
> at (SOHO) routers that have absurd (multi-second) buffers, the
> concepts at play work here as well.

While your reasoning holds truth it does not explain why the expensive
chassis solution (good) makes my customers happy, and the cheaper TOR
solution makes my customers unhappy.....

Bufferbloat does not matter to them as jitter and latency does not matter.
As long as the TCP window size negotioation is not reset the total
amount of bit/sec increases for them.

If deep buffers are bad I would expect high-end chassis solutions not
to offer them either.
But the market seems to offer expensive deep buffer chassis solutions
and cheap (per 10GE) TOR solutions.
IMHO there is no reasoning why....
(why the expensive solution is not offered in a 1U box)

My customers want to buffer 10 to 24 * 10GE in a 1 or 2 10GE uplinks
to do this they need some buffers....

Bas



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