nanog mailing list archives
RE: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3)
From: Leigh Porter <leigh.porter () ukbroadband com>
Date: Tue, 28 Jun 2011 10:29:56 +0000
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:jerome () 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 <eugen () leitl org>:----- Forwarded message from William Salt<williamejsalt () googlemail com> -----From: William Salt <williamejsalt () googlemail com> Date: Tue, 28 Jun 2011 08:03:25 +0100 To: support () pfsense com Subject: [pfSense Support] Strange TCP connection behavior 2.0 RC2(+3)Reply-To: support () 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 serverwith anintel quad port NIC running pfsense 2 (RC2 at one end RC3 at theother) andthe IGB driver on the quad port. We can pass 1gbps either way with UDP. However we are experiencingverystrange issues with tcp connections. With window scaling enabled, and a max socket buffer set to 16MB, wesee nodifference. Even disabling window scaling and setting the window to 16MB makes no difference. Each TCP connection starts very slowly, and will max out at around190mbps,taking nearly 2 minutes to climb to this speed before *plateauing*. We have to initiate many (5+) connections to saturate the link withtcpconnections with iperf. Real world tests transferring files, max out at 100mbps, usingmultipleconnections. I have followed guides like this: http://www.psc.edu/networking/projects/tcptune/#FreeBSD With no luck, and have tweaked, disabled, and enabled nearly everyrelevantsysctl parameter with no luck. Can anyone shed some light on this? I am now doubting the IGB driver, and am looking to swap out thecards as alast ditch effort. However, we have tried different hardware (L3 switches, mediaconvertes +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 canhelp 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 ______________________________________________________________________
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Current thread:
- [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Eugen Leitl (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Jérôme Nicolle (Jun 28)
- RE: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Leigh Porter (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Mikael Abrahamsson (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) kristopher . doyen (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Dobbins, Roland (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Rhys Rhaven (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Andreas Ott (Jun 28)
- RE: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Leigh Porter (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Cameron Byrne (Jun 28)
- RE: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Leigh Porter (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Cameron Byrne (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) PC (Jun 28)
- RE: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Leigh Porter (Jun 28)
- Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3) Jérôme Nicolle (Jun 28)