Date: Wed, 29 Jul 2009 14:17:08 +0400 From: Anthony Pankov <ap00@mail.ru> To: freebsd-net@freebsd.org Subject: TCP initial window size Message-ID: <98265976953.20090729141708@mail.ru>
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Can anybody explain me about initial TCP window sent to the client (in syn/ack packet),
please.
Is it unmanageable and always set to net.inet.tcp.recvspace?
(Due to use of syncache and syncache code is (tcp_syncache.c):
/* Initial receive window: clip sbspace to [0 .. TCP_MAXWIN] */
win = sbspace(&so->so_rcv);
win = imax(win, 0);
win = imin(win, TCP_MAXWIN);
sc->sc_wnd = win;
)
If it is, then what bad things will happen if i replace code above by
code like this:
if (tcp_do_rfc3390)
sc->sc_wnd = min(4*(sc->sc_peer_mss ? sc->sc_peer_mss:tcp_mssdflt ),
max(2 * (sc->sc_peer_mss ? sc->sc_peer_mss:tcp_mssdflt), 4380));
else
sc->sc_wnd = (sc->sc_peer_mss ? sc->sc_peer_mss:tcp_mssdflt) * ss_fltsz;
Also, does local connection use syncache?
System: FreeBSD 6.2-RELEASE-p9
--
Best regards,
Anthony mailto:ap00@mail.ru
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