Path: utzoo!utgpu!watserv1!watmath!att!pacbell.com!ames!sun-barr!lll-winken!lll-crg.llnl.gov
From: booloo@lll-crg.llnl.gov (Mark Boolootian)
Newsgroups: comp.protocols.tcp-ip
Subject: Can a receiving application change window size?
Message-ID: <87439@lll-winken.LLNL.GOV>
Date: 7 Dec 90 16:51:52 GMT
Sender: usenet@lll-winken.LLNL.GOV
Organization: Lawrence Livermore National Laboratory
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Nntp-Posting-Host: lll-crg.llnl.gov


I have been under the impression that the window presented by a TCP receiver is
tied to the amount of socket buffer available.  Thus, if I setsockopt() and
change the socket receive buffer size, I would note a change in the size of
the receive window.  Unfortunately, after looking at some ethernet traces, I
have found this not to be the case.  I have looked (briefly and without a lot
of comprehension) at the BSD4.3 (Ultrix flavored) source and it sure looked like
the receive window was tied to the size of the socket buffer. But the window
presented by our vax is always 4K, even when I set a receive buffer size of
32K.

So my question is:

Is there any way for an application (who wishes to receive data) to increase
the window presented to the sender?

Many thanks in advance,
mb
booloo@lll-crg.llnl.gov

btw, I had previously asked how it was possible for bind() to return EADDRINUSE
once SO_REUSEADDR had been set on a socket.  Unfortunately, nobody has been able
to provide (what I consider to be) a satisfactory answer.  I'd still really like
to know...