Date: Wed, 4 Sep 1996 00:44:23 +0200 (MET DST) From: Luigi Rizzo <luigi@labinfo.iet.unipi.it> To: hackers@freebsd.org Subject: cwnd problem with PPP Message-ID: <199609032244.AAA08098@labinfo.iet.unipi.it>
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I am not sure if this is a bug or not...
when a tcp connection is opened, snd_cwnd is set to 1073725440
and is only put back to 1 mss in tcp_mss(), but only for _non_local_
communication. This saves the overhead of slow start on local comms.
but blasts a full window of data at the beginning of a connection.
This might be troublesome on a serial link.
(on the other hand, setting cwnd to 1mss only might force the
connection to experience a delayed ack since there is not enough
data to trigger a window update and immediate ack; but this is not my
problem now)
Now, I am not sure if PPP connections (I am using iijppp) are
considered local or not.
I have the following in /etc/ppp/ppp.conf:
set ifaddr 131.114.9.11 131.114.9.242 255.255.255.0
and still connections to 131.114.X.X seem not to reset properly
snd_cwnd, despite the 24-bit netmask I use. I am running stock 2.1R
with updated in_rmx.c from -stable.
Can anyone comment on this ?
Luigi
====================================================================
Luigi Rizzo Dip. di Ingegneria dell'Informazione
email: luigi@iet.unipi.it Universita' di Pisa
tel: +39-50-568533 via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522 http://www.iet.unipi.it/~luigi/
====================================================================
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