decreasing Swind/Rwind values from netstat output

From: June-young Jang (flips1_at_hanmir.com)
Date: 07/09/03 

Date: 8 Jul 2003 18:08:46 -0700

Hi, my question is about tcp socket programming.

I traced a connection between client and server
between client and server. I continuously checked the connection
using "netstat" command. The values for Swind and Rwind from
netstat output are decreased, and finnaly send() in client returns
with errno=EPIPE (broken pipe) and the connection is away.

My questions are
1. what is the exactly meaning of the four fields(Swind/Send-Q/Rwind/Recv-Q)
   in netstat output? (netstat man page doesn't say about them.)
2. why does this situation(decreasing Swind/Rwind) occur
   and how do I fix it?

Four values in below are "Swind Send-Q Rwind Recv-Q",
and I am working on Solaris 8.

# netstat -na|grep 43613
127.0.0.1.43613 127.0.0.1.6666 4724 579 0 0 ESTABLISHED
127.0.0.1.6666 127.0.0.1.43613 0 0 4144 580 ESTABLISHED
# netstat -na|grep 43613
127.0.0.1.43613 127.0.0.1.6666 1880 551 0 0 ESTABLISHED
127.0.0.1.6666 127.0.0.1.43613 0 0 1880 552 ESTABLISHED
# netstat -na|grep 43613
127.0.0.1.43613 127.0.0.1.6666 1880 579 0 0 ESTABLISHED
127.0.0.1.6666 127.0.0.1.43613 0 0 1300 580 ESTABLISHED
# netstat -na|grep 43613
127.0.0.1.43613 127.0.0.1.6666 196 0 0 0 ESTABLISHED
127.0.0.1.6666 127.0.0.1.43613 0 0 196 0 ESTABLISHED
# netstat -na|grep 43613
127.0.0.1.43613 127.0.0.1.6666 196 0 0 0 ESTABLISHED
127.0.0.1.6666 127.0.0.1.43613 0 0 196 0 ESTABLISHED
# netstat -na|grep 43613
127.0.0.1.43613 127.0.0.1.6666 196 0 0 0 ESTABLISHED
127.0.0.1.6666 127.0.0.1.43613 0 0 196 0 ESTABLISHED
# netstat -na|grep 43613
#

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