Indeed, we had similar issues on a 3G radio network. Long RTTs made it impossible to reach the maximum potential throughput of the network. I installed one of these:
http://www.fastsoft.com/home/ And the problem just went away. -- Leigh Porter > -----Original Message----- > From: Jérôme Nicolle [mailto:jer...@ceriz.fr] > Sent: 28 June 2011 11:26 > To: Eugen Leitl > Cc: NANOG list > Subject: Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 > (+3) > > This is a well known issues called "Long Fat Pipe Network". > > There's many university papers about it and many tricks to get around > it on software-based boxes. > > Adjusting your TCP window size was the best start, if it's set > properlu. The basic formula is provided in this forum post : > http://forums.whirlpool.net.au/archive/116165 > > Good luck ! > > 2011/6/28 Eugen Leitl <eu...@leitl.org>: > > ----- Forwarded message from William Salt > <williamejs...@googlemail.com> ----- > > > > From: William Salt <williamejs...@googlemail.com> > > Date: Tue, 28 Jun 2011 08:03:25 +0100 > > To: supp...@pfsense.com > > Subject: [pfSense Support] Strange TCP connection behavior 2.0 RC2 > (+3) > > Reply-To: supp...@pfsense.com > > > > Hi All, > > For the last couple of months i have been pulling my hair out > > trying to solve this problem. > > We have a 1Gbps transatlantic link from the UK to the US, which has > > successfully passed the RFC2544 test. > > > > At either end, we have a media converter, and a supermicro server > with an > > intel quad port NIC running pfsense 2 (RC2 at one end RC3 at the > other) and > > the IGB driver on the quad port. > > > > We can pass 1gbps either way with UDP. However we are experiencing > very > > strange issues with tcp connections. > > > > With window scaling enabled, and a max socket buffer set to 16MB, we > see no > > difference. > > Even disabling window scaling and setting the window to 16MB makes no > > difference. > > > > Each TCP connection starts very slowly, and will max out at around > 190mbps, > > taking nearly 2 minutes to climb to this speed before *plateauing*. > > > > We have to initiate many (5+) connections to saturate the link with > tcp > > connections with iperf. > > > > Real world tests transferring files, max out at 100mbps, using > multiple > > connections. > > > > I have followed guides like this: > > http://www.psc.edu/networking/projects/tcptune/#FreeBSD > > > > With no luck, and have tweaked, disabled, and enabled nearly every > relevant > > sysctl parameter with no luck. > > > > Can anyone shed some light on this? > > > > I am now doubting the IGB driver, and am looking to swap out the > cards as a > > last ditch effort. > > However, we have tried different hardware (L3 switches, media > convertes + > > laptops etc), and the symptoms still persist... > > The only constant is freebsd 8.1 - pfsense (or 8.2 for our production > > systems). > > I have tried the freebsd net mailinglist, but im hoping you lot can > help me! > > > > Cheers in advance > > Will > > > > ----- End forwarded message ----- > > -- > > Eugen* Leitl <a href="http://leitl.org";>leitl</a> http://leitl.org > > ______________________________________________________________ > > ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org > > 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE > > > > > > > > -- > Jérôme Nicolle > 06 19 31 27 14 > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please visit http://www.messagelabs.com/email > ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
