From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nm27-vm8.access.bullet.mail.gq1.yahoo.com (nm27-vm8.access.bullet.mail.gq1.yahoo.com [216.39.63.235]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 918D321F108 for ; Sun, 15 Mar 2015 17:42:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rogers.com; s=s2048; t=1426466574; bh=ee1s86eVikXpRIF3g6MDUoYGMLBtWL7wEj3xdYga8X8=; h=Date:From:Reply-To:To:Subject:References:In-Reply-To:From:Subject; b=OsAy5FZ8DkLNnOvsbQNgC4rO2Qif1o8EuxWSYl/ci2e/MgUzAqqk4bfJHzC9wBTr7+0whf3MgaymzWTXIXTNM7NjEFpM5x83FdwmgmT8t6d75+N96l6DrVC+UZL5ZYGXdVveDOP9pIque+E+h6y7fUAcFnFD2BK554IHhhbiJb3dT7OhIKwU3WHeNGnftNyayuAhVJ5R7Z18S6V3rFNUqVDUM6n+RwLGEqfkk3dh0b0yfYQCuo8cOtd4ROAyvZspYyfv+sFYsE3wsYYsVPWZP4UFh6u2Xf6Ly4Un0Umhrs1fUQBZ735HcZBrzi5P7lNkzD8RXx47oyvTW1bvLE7fNw== Received: from [216.39.60.173] by nm27.access.bullet.mail.gq1.yahoo.com with NNFMP; 16 Mar 2015 00:42:54 -0000 Received: from [98.138.226.241] by tm9.access.bullet.mail.gq1.yahoo.com with NNFMP; 16 Mar 2015 00:42:54 -0000 Received: from [127.0.0.1] by smtp112.sbc.mail.ne1.yahoo.com with NNFMP; 16 Mar 2015 00:42:53 -0000 X-Yahoo-Newman-Id: 970755.39215.bm@smtp112.sbc.mail.ne1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: 1ObWWwUVM1lv8b7._XpCVxHtLVv4ESNZNwyQljfWlmMed3l rrGO8ahXLHU5YMxOV7LhLA10xL.vwGHFeAskTohXqoFcPj93qVj4z.u9Bjsb padl.HNpWQOpTKqHd1nhy5.IYMFjAZNg1mjwlMvxcapPlCggCXApYiGyLHP9 x6BNG2afGOBrq5HIIl8o8ixdH.Ai55TZ6Oa5xNqo4xtMC75njJyeGbCr1bdR Zdu8sMB4shz_H5K0HP.shsUjitkTln7CXvoIqbbINl7bHjUC3rSJBxalphHY JTK08mWVIR6H7O6U.jQ1AXrKCU0nIFqOBJfCqOf5trJFKKSDZelGug4aarNb hISGPl7Fp1Y2iG7HwbaH0i2fjq2huMotULWh3pAFFkQCLQdsyvjhOkZCJTbD HyvBuSS0vuOwKrYk9lzgavkrGL.cHyRTOy_ipwBAeHpcV3ldmpv5_0QuLrAW EnM03HSUmskq_KT7wSMZKI_CTXwtNWSXtZq.oP9r_d7Cctw5PjvcJDXbB9Ul a6XrepSGMXlMX_2TrIWdn6TIOxvpR8IqWK9Z2 X-Yahoo-SMTP: sltvjZWswBCRD.ElTuB1l9j6s9wRYPpuyTNWOE5oEg-- Message-ID: <5506270C.2000005@rogers.com> Date: Sun, 15 Mar 2015 20:42:52 -0400 From: David Collier-Brown User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: "codel@lists.bufferbloat.net" References: <5504E8F8.3050203@rogers.com> In-Reply-To: <5504E8F8.3050203@rogers.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Codel] Latency vs Delay X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list Reply-To: davecb@spamcop.net List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Mar 2015 00:43:23 -0000 On 03/14/2015 10:05 PM, David Collier-Brown wrote: > On 03/14/2015 03:00 PM, divya singla asked >> Hi Members, >> is there anybody who can explain me difference between latency and >> delay? > In queuing, latency is the time between the send and the first byte of > the reply, and (total) response time is the time between the send and > the last byte of the reply. The time between first and last byte is > the transfer time. Both are stated as if they were being observed by a > client, either nearby or remote. > > Delay, on the other hand, is the time the job spends sitting in a > queue waiting to start work. Service time is the time it takes to do > the work. Both are specifically at the server, or "queuing center" > > If you draw a diagram, they overlap inconveniently (;-)) > > --dave > > > For example, in \ |- queue delay |- service time /|- more service time | / The latency is the time from \ to the first /, and it contains the network time, the queuing delay and all the service time required to get to the first byte of the reply. The transfer time is from the \ to the last /, and includes and additional service time to get to the last byte of the reply --dave -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest davecb@spamcop.net | -- Mark Twain