From owner-freebsd-hackers Thu Jul 15 10:10:32 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id 7C88015591 for ; Thu, 15 Jul 1999 10:10:25 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id KAA11425; Thu, 15 Jul 1999 10:08:29 -0700 (PDT) (envelope-from dillon) Date: Thu, 15 Jul 1999 10:08:29 -0700 (PDT) From: Matthew Dillon Message-Id: <199907151708.KAA11425@apollo.backplane.com> To: "John W. DeBoskey" Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: tcp windowsize query? References: <199907151549.LAA78679@bb01f39.unx.sas.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG : If I may re-phrase.. How do I determine if the send/recv spaces :are large enough, and if not, how many times I bumped into the :wall? : :Thanks! :John It depends entirely on the type of traffic your machine is handling. A large web server usually uses relatively small (16K or 32K) window sizes in order to avoid wasting memory. It might be handling a thousand active connections. A machine that is running over a long haul fiber or over a very fast link might want to use larger window sizes to keep the pipeline full, but only if it really needs to max out per-connection bandwidth. A machine that is running over slower links can make due with smaller tcp window sizes. Or perhaps if you have a machine running over a very slow link, like a modem link, you may want to significantly reduce the tcp window size for bulk transfers in order to get better interactive performance. e.g. working over a remote connection while at the same time downloading a big tar file via ftp or a browser. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message