From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Date: Thu, 29 May 2008 15:06:11 +0000 Subject: Re: receiver window questions Message-Id: <483EC663.1070805@hp.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sctp@vger.kernel.org Hi Michael Michael Tuexen wrote: > Hi Vlad, > > we are currently testing the receive behaviour of Linux (and > other systems). > > We are using Fedora 9, kernel 2.6.25-14. > > The receiver application just opens a 1-to-many style socket > and sleeps forever, not reading any messages. > > The sender (on a different machine), sends a lot of messages of the > same size, all on stream 0, ordered. > > When setting the receive buffer space (using the SO_RCVBUF socket option) > to 10000 we oberserve the following: > > - When sending messages of size 1000 bytes, the receiver SACK the first, > announces 9000 bytes windows, SACKs the second announces 8000 bytes > and so on. Look fine. The a_rwnd goes down to 0 and discards messages. > Everything is fine. > > - When sending messages of size 100 bytes, the receiver SACKs the first > messages and reduces the a_rwnd accordingly. Then it looks like the > receive buffer grows, because messages are accepted and the a_rwnd does > not shrink. Is this intended? No. The a_rwnd should go down to 0 as before. > We also figured out that after about 670947 messages of size 100 bytes > the association is aborted. Is this intended? This is also not intended. We'll take a look. Thanks -vlad > > - Sending messages of size 10 bytes is similar to 100 byes. > > Best regards > Michael > >