From owner-freebsd-net@FreeBSD.ORG Wed May 13 00:13:31 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 0C796441 for ; Wed, 13 May 2015 00:13:31 +0000 (UTC) Received: from vps.hungerhost.com (vps.hungerhost.com [216.38.53.176]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D42851B18 for ; Wed, 13 May 2015 00:13:30 +0000 (UTC) Received: from pool-108-54-164-204.nycmny.fios.verizon.net ([108.54.164.204]:51087 helo=[192.168.1.17]) by vps.hungerhost.com with esmtpsa (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.82) (envelope-from ) id 1YsKIi-0001Q3-8O; Tue, 12 May 2015 20:13:28 -0400 From: "George Neville-Neil" To: "Karlis Laivins" Cc: "Eggert, Lars" , "freebsd-net@freebsd.org" , "grenville armitage" Subject: Re: Congestion Control Modification Date: Tue, 12 May 2015 20:13:27 -0400 Message-ID: <7B9881D7-F321-48F8-A38A-7B0D0B147F71@neville-neil.com> In-Reply-To: References: <5535945F.90504@swin.edu.au> <98E7D40A-EC37-413D-85CE-2A6012811E08@netapp.com> <8D3AEF2A-1413-4C44-9E5C-66900847F18A@neville-neil.com> MIME-Version: 1.0 Content-Type: text/plain; format=flowed X-Mailer: MailMate (1.9.1r5084) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - vps.hungerhost.com X-AntiAbuse: Original Domain - freebsd.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - neville-neil.com X-Get-Message-Sender-Via: vps.hungerhost.com: authenticated_id: gnn@neville-neil.com X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 May 2015 00:13:31 -0000 Sounds good. Best, George On 1 May 2015, at 1:21, Karlis Laivins wrote: > Hello George, > > Thank you for the tip! I have set up a virtual test environment with > IMUNES > (interesting tool, by the way) and now I am running validation tests, > to > see, if the results there are at least similar to those that can be > achieved on a physical testbed. > > I will let you know if and when the implementation will be done as I > will > certainly need objective feedback. > > BR, > Karlis > > On Fri, May 1, 2015 at 12:06 AM, George Neville-Neil > > wrote: > >> If you want to run some experiments, though, you could look at >> running PTPd >> on 3 servers (master, and two slaves) which will get you decent >> synchronization >> among the three. Where decent is less than the typical RTT of a TCP >> packet on a >> 1Gbps LAN. >> >> Best, >> George >> >> >> On 30 Apr 2015, at 14:48, Karlis Laivins wrote: >> >> Yes, you are correct, I meant to write "relative OWD". As David Hayes >> put >>> it - "Relative OWD measurements are easier, and clock drift is not >>> usually >>> a problem over the time it takes to send and receive an ACK". >>> >>> Thank you for the correction! >>> >>> On Thu, Apr 30, 2015 at 4:19 PM, Eggert, Lars >>> wrote: >>> >>> On 2015-4-30, at 15:04, Karlis Laivins >>> wrote: >>>> >>>>> I have yet to solve the issue of >>>>> how to get the One Way Delay for the ACK message (the time it >>>>> takes ACK >>>>> >>>> to >>>> >>>>> arrive from receiver of the ACK'ed data sender) correctly. >>>>> >>>> >>>> That won't work without synchronized clocks, which you can't really >>>> assume >>>> to be present. >>>> >>>> Lars >>>> >>>