Commit Graph

22 Commits

Author SHA1 Message Date
Alfred Perlstein
e88894d39a make the strings for tcptimers, tanames and prurequests const to silence
warnings.
2002-08-16 09:07:59 +00:00
Matthew Dillon
701bec5a38 Introduce two new sysctl's:
net.inet.tcp.rexmit_min (default 3 ticks equiv)

    This sysctl is the retransmit timer RTO minimum,
    specified in milliseconds.  This value is
    designed for algorithmic stability only.

net.inet.tcp.rexmit_slop (default 200ms)

    This sysctl is the retransmit timer RTO slop
    which is added to every retransmit timeout and
    is designed to handle protocol stack overheads
    and delayed ack issues.

Note that the *original* code applied a 1-second
RTO minimum but never applied real slop to the RTO
calculation, so any RTO calculation over one second
would have no slop and thus not account for
protocol stack overheads (TCP timestamps are not
a measure of protocol turnaround!).  Essentially,
the original code made the RTO calculation almost
completely irrelevant.

Please note that the 200ms slop is debateable.
This commit is not meant to be a line in the sand,
and if the community winds up deciding that increasing
it is the correct solution then it's easy to do.
Note that larger values will destroy performance
on lossy networks while smaller values may result in
a greater number of unnecessary retransmits.
2002-07-18 19:06:12 +00:00
Matthew Dillon
22fd54d461 I don't know how the minimum retransmit timeout managed to get set to
one second but it badly breaks throughput on networks with minor packet
loss.

Complaints by: at least two people tracked down to this.
MFC after:	3 days
2002-07-17 23:32:03 +00:00
Alfred Perlstein
4d77a549fe Remove __P. 2002-03-19 21:25:46 +00:00
Peter Wemm
664a31e496 Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot).  This is consistant with the other
BSD's who made this change quite some time ago.  More commits to come.
1999-12-29 04:46:21 +00:00
Jonathan Lemon
c0a929b430 Change the delayed ack time from 200ms to 100ms.
This results in closer behavior to earlier versions, where the fixed
200ms timer actually resulted in a delay anywhere from 1..200ms, with
the average delay being 100ms.

Pointed out by:	 dg
1999-12-02 03:25:19 +00:00
Jonathan Lemon
9987d77844 Remove conversion macros that were used during development. 1999-08-31 16:31:07 +00:00
Jonathan Lemon
9b8b58e033 Restructure TCP timeout handling:
- eliminate the fast/slow timeout lists for TCP and instead use a
    callout entry for each timer.
  - increase the TCP timer granularity to HZ
  - implement "bad retransmit" recovery, as presented in
    "On Estimating End-to-End Network Path Properties", by Allman and Paxson.

Submitted by:	jlemon, wollmann
1999-08-30 21:17:07 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Bruce Evans
bea0f0be7b Some staticized variables were still declared to be extern. 1997-09-07 05:27:26 +00:00
Peter Wemm
6875d25465 Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.
1997-02-22 09:48:43 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
Paul Traina
7b40aa327d Make the misnamed tcp initial keepalive timer value (which is really the
time, in seconds, that state for non-established TCP sessions stays about)
a sysctl modifyable variable.

[part 1 of two commits, I just realized I can't play with the indices as
 I was typing this commit message.]
1996-09-13 23:51:44 +00:00
Garrett Wollman
51fb392203 Better selection of initial retransmit timeout when no cached
RTT information is available.

Submitted by: kbracey@art.acorn.co.uk (Kevin Bracey)
(slightly modified by me)
1996-06-14 17:17:32 +00:00
Mike Pritchard
6c5e9bbdf5 Fix a bunch of spelling errors in the comment fields of
a bunch of system include files.
1996-01-30 23:02:38 +00:00
Poul-Henning Kamp
0312fbe97d New style sysctl & staticize alot of stuff. 1995-11-14 20:34:56 +00:00
Garrett Wollman
2f96f1f446 Get rid of some unneeded #ifdef TTCP lines. Also, get rid of some
bogus commons declared in header files.
1995-02-14 02:35:19 +00:00
Garrett Wollman
eb6ad69646 Merge in T/TCP TCP header file changes. 1995-02-08 20:18:48 +00:00
Paul Richards
707f139edb Made idempotent.
Submitted by:	Paul
1994-08-21 05:27:42 +00:00
David Greenman
3c4dd3568f Added $Id$ 1994-08-02 07:55:43 +00:00
Rodney W. Grimes
26f9a76710 The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch.
Reviewed by:	Rodney W. Grimes
Submitted by:	John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
Rodney W. Grimes
df8bae1de4 BSD 4.4 Lite Kernel Sources 1994-05-24 10:09:53 +00:00