From owner-freebsd-questions Fri Apr 9 16:28: 0 1999 Delivered-To: freebsd-questions@freebsd.org Received: from resnet.uoregon.edu (resnet.uoregon.edu [128.223.144.32]) by hub.freebsd.org (Postfix) with ESMTP id 2949014D18 for ; Fri, 9 Apr 1999 16:27:57 -0700 (PDT) (envelope-from dwhite@resnet.uoregon.edu) Received: from localhost (dwhite@localhost) by resnet.uoregon.edu (8.8.8/8.8.8) with ESMTP id QAA15261; Fri, 9 Apr 1999 16:25:41 -0700 (PDT) (envelope-from dwhite@resnet.uoregon.edu) Date: Fri, 9 Apr 1999 16:25:41 -0700 (PDT) From: Doug White To: Emmanuel Duros Cc: freebsd-questions@FreeBSD.ORG Subject: Re: RFC 1323 - How to make it work ? In-Reply-To: <199904091349.PAA09809@chouette.inria.fr> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 9 Apr 1999, Emmanuel Duros wrote: > > Hi, > > I am trying to get speed improvement using RFC 1323 to download files > via a satellite link without much success(!). > > I have 2 FreeBSD (2.2.7) boxes (bsd 1 and bsd 2) which are connected via > a broadcast satellite link and an Ethernet LAN. > > satellite link 6Mbps > --------->------------>------------>---------- > | | > ------- ------- > |bsd 1| |bsd 2| > ------- ------- > | | > ---------------------------------------------- > Ethernet LAN 10Mbps > > Routing is configured in such way: > > - bsd 1 sends packets to bsd 2 via the sat link > - bsd 2 send packets to bsd 1 vian the LAN > > The RTT is about 270ms. This is a problem. Big latency throws TCP for a loop. Thus why there's a TCP over Satellite working group. > When downloading a file (client is bsd 1 and server is bsd 2), the > maximum data rate I have been able to get on this topology is > 50-60 Kbytes/s. Although I don't have my magic network text handy, it sounds about right for your link. > Am I doing anything wrong ? I also played with net.inet.tcp.rfc1644 > without success. I don't think T/TCP is going to help here. The thing about sat links is they can aggregate bandwidth well but can't sustain high rates. This is also why one ISDN channel can push around more data than a similarly equipped analog modem. Doug White Internet: dwhite@resnet.uoregon.edu | FreeBSD: The Power to Serve http://gladstone.uoregon.edu/~dwhite | www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message