svn commit: r242261 - head/sys/netinet

[Andre Oppermann]

On 28.10.2012 23:01, Rui Paulo wrote:
> On Oct 28, 2012, at 14:56, Andre Oppermann <andre at freebsd.org> wrote:
>
>> On 28.10.2012 22:34, Rui Paulo wrote:
>>> On 28 Oct 2012, at 12:02, Andre Oppermann <andre at FreeBSD.org> wrote:
>>>
>>>> Author: andre
>>>> Date: Sun Oct 28 19:02:07 2012
>>>> New Revision: 242261
>>>> URL: http://svn.freebsd.org/changeset/base/242261
>>>>
>>>> Log:
>>>>   For retransmits of SYN|ACK from the syncache use the slightly more
>>>>   aggressive special tcp_syn_backoff[] retransmit schedule instead of
>>>>   the normal tcp_backoff[] schedule for established connections.
>>>
>>>
>>> How did you came up with the values for tcp_syn_backoff? I obviously
>>> understand the aggressiveness, but did you measure any significant
>>> improvement in connection establishment time and if so, on what type of links?
>>
>> I didn't come up with the values.  tcp_syn_backoff[] was introduced
>> almost 12 years ago by jlemon.  For syncache it got lost somewhere
>> along the line.
>
> Oh, I see. I read it backwards.
>
>>
>> There has been recent talk by some large FreeBSD web server operators
>> of reducing SYN|ACK retransmit timeouts.  This change fixes a part of
>> the problem.  The recent RFC on reducing the RTO will fix the other
>> part.
>
> Which RFC? I'm only aware of draft-hurtig-tcpm-rtorestart.

RFC6298.

-- 
Andre