From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from oproxy1-pub.bluehost.com (oproxy1-pub.bluehost.com [66.147.249.253]) by huchra.bufferbloat.net (Postfix) with SMTP id DDBF5201A56 for ; Mon, 16 May 2011 06:32:32 -0700 (PDT) Received: (qmail 23943 invoked by uid 0); 16 May 2011 13:42:10 -0000 Received: from unknown (HELO host291.hostmonster.com) (74.220.215.91) by cpoproxy1.bluehost.com with SMTP; 16 May 2011 13:42:10 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=avanw.com; h=Received:From:To:References:In-Reply-To:Subject:Date:Organization:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Mailer:Thread-Index:Content-Language:X-Identified-User; b=BsmESWYZ31uTG//kZg9NAv1IuoV4dZkTtQ+8sKiLrWKhD8wMobnrq6ngKa1pHIxW6ZqpvW+1+g+oqYt0u66CgSCqze/nX91f9fM3fEk/bsI9ra/SIIrMW/KJ3zyI1u9Z; Received: from c-76-120-76-232.hsd1.co.comcast.net ([76.120.76.232] helo=AVADesk2) by host291.hostmonster.com with esmtpa (Exim 4.69) (envelope-from ) id 1QLy3m-0001t1-Bw for bloat@lists.bufferbloat.net; Mon, 16 May 2011 07:42:10 -0600 From: "Kevin Gross" To: References: <4DB70FDA.6000507@mti-systems.com> <4DC2C9D2.8040703@freedesktop.org> <20110505091046.3c73e067@nehalam> <6E25D2CF-D0F0-4C41-BABC-4AB0C00862A6@pnsol.com> <35D8AC71C7BF46E29CC3118AACD97FA6@srichardlxp2> <1304964368.8149.202.camel@tardy> <4DD9A464-8845-49AA-ADC4-A0D36D91AAEC@cisco.com> <1305297321.8149.549.camel@tardy><014c01cc11a8$de78ac10$9b6a0430$@gross@avanw.com><8A928839-1D91-4F18-8252-F06BD004E37D@cisco.com><5946BA6B-4E00-43AF-A8A2-17FB3769F37B@cisco.com> <2EEFB9D5-E9CC-4612-8D91-F6B382E3C2FB@gmail.com> <13672E5D-7EAE-446A-A8D8-BA85EF2CE72E@cisco.com> <4DD10938.7020703@freedesktop.o rg> <012d01cc13cb$61617ed0$24247c70$@gross@avanw.com> <4DD12520.8050604@freedesktop.org> In-Reply-To: <4DD12520.8050604@freedesktop.org> Date: Mon, 16 May 2011 07:42:01 -0600 Organization: AVA Networks Message-ID: <013401cc13cf$098ee720$1cacb560$@gross@avanw.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: AcwTzFqHku77HLX0QY6Z8DOvscfhOAAAI+eQ Content-Language: en-us X-Identified-User: {1416:host291.hostmonster.com:avanwcom:avanw.com} {sentby:smtp auth 76.120.76.232 authed with kevin.gross@avanw.com} Subject: Re: [Bloat] Jumbo frames and LAN buffers X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 May 2011 13:32:33 -0000 I would like to try this. Can you suggest specific equipment to look at. Due to integration and low port count, most of the cheap consumer stuff has surprisingly good layer-2 performance. I've tested a bunch of Linksys and other small/medium business 5 to 24 port gigabit switches. Since I measure latency, I expect I would have noticed if flow control were kicking in. Kevin Gross -----Original Message----- From: bloat-bounces@lists.bufferbloat.net [mailto:bloat-bounces@lists.bufferbloat.net] On Behalf Of Jim Gettys Sent: Monday, May 16, 2011 7:23 AM To: bloat@lists.bufferbloat.net Subject: Re: [Bloat] Jumbo frames and LAN buffers On 05/16/2011 09:15 AM, Kevin Gross wrote: > All the stand-alone switches I've looked at recently either do not support > 802.3x or support it in the (desireable) manner described in the last > paragraph of the linked blog post. I don't believe Ethernet flow control is > a factor in current LANs. I'd be interested to know the specifics if anyone > sees it differently. Heh. Plug wireshark into current off the shelf cheap consumer switches intended for the home. You won't like what you see. And you have no way to manage them. I was quite surprised last fall when doing my home experiments to see 802.3 frames; I had been blissfully unaware of its existence, and had to go read up on it as a result. I don't think any of the enterprise switches are so brain damaged. So i suspect it's mostly lurking to cause trouble in home and small office environments, exactly where no-one will know what's going on. - Jim