From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-x232.google.com (mail-qa0-x232.google.com [IPv6:2607:f8b0:400d:c00::232]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id EBD2E200664; Sun, 28 Apr 2013 07:56:29 -0700 (PDT) Received: by mail-qa0-f50.google.com with SMTP id dx4so724047qab.2 for ; Sun, 28 Apr 2013 07:56:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:content-type:mime-version:subject:from:in-reply-to:date :cc:content-transfer-encoding:message-id:references:to:x-mailer; bh=GZDtiWV5SrEbGh6HbVatqhgvnE3xGWBwEyhGqW11GfY=; b=oK7cz4n/5oMaoFF6t8T2KJqghWdXcF147ej7qZmLRCR/McR8ebNlvPAP/S1OzXbsD7 oULh1RXxPIYf5k9/TdVQDkMkU9NNjuY2Aaia4F1C/+Cb9HJz3+ZRKL7fqIRpVJgGtPLF GcXwyi+WcJS0cHmgvTtc9EFxTA1O1mRjnqAvaB63ig38jrhnWuyt9fLc0Jmarco/miBH 0WN7EThMoaZjHu69sLaXTOuq2xfe0ZAGBNyn84FwO3E1s9OU+DVTl/jxlouzydilKIyA j30O4k0rUtlHXoTOzTSCQ+JEUo8FVkdO2t0owT0pR+rMbHs7ZXX7AKeUy3wENZZXmiCt LxsA== X-Received: by 10.49.97.130 with SMTP id ea2mr56866957qeb.23.1367160988433; Sun, 28 Apr 2013 07:56:28 -0700 (PDT) Received: from [172.30.42.120] (pool-64-222-211-82.port.east.myfairpoint.net. [64.222.211.82]) by mx.google.com with ESMTPSA id u3sm29138833qab.1.2013.04.28.07.56.27 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 28 Apr 2013 07:56:27 -0700 (PDT) Content-Type: text/plain; charset=iso-8859-1 Mime-Version: 1.0 (Mac OS X Mail 6.3 \(1503\)) From: Rich Brown In-Reply-To: Date: Sun, 28 Apr 2013 10:56:26 -0400 Content-Transfer-Encoding: quoted-printable Message-Id: References: To: Dave Taht X-Mailer: Apple Mail (2.1503) X-Mailman-Approved-At: Wed, 01 May 2013 09:16:18 -0700 Cc: codel@lists.bufferbloat.net, cerowrt-devel@lists.bufferbloat.net, bloat Subject: Re: [Codel] [Bloat] blip: a tool for seeing internet latency with javascript X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Apr 2013 14:56:30 -0000 This is indeed a cool hack. I was astonished for a moment, because it = was a bedrock belief that you can't send pings from Javascript. And in = fact, that is still true. Apenwarr's code sends short HTTP queries of the format shown below to = each of two hosts:=20 http://gstatic.com/generate_204 http://apenwarr.ca/blip/ The Blip tool shows ~60-70ms for the gstatic host, and ~130 msec for the = latter. Ping times are ~52 msec and 125msec, respectively. These times = seem to track response times by my eye (no serious analysis) to load = both on my primary (bloated) router and CeroWrt. Still a cool hack. Rich ------------------------- HTTP Request & Response for typical blip "ping" OPTIONS /generate_204 HTTP/1.1 Host: gstatic.com Connection: keep-alive Access-Control-Request-Method: GET Origin: http://gfblip.appspot.com User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) = AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.65 Safari/537.31 Access-Control-Request-Headers: accept, origin, x-requested-with Accept: */* Referer: http://gfblip.appspot.com/ Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=3D0.8 Accept-Charset: ISO-8859-1,utf-8;q=3D0.7,*;q=3D0.3 HTTP/1.1 204 No Content Content-Length: 0 Content-Type: text/html; charset=3DUTF-8 Date: Sun, 28 Apr 2013 12:37:17 GMT Server: GFE/2.0 On Apr 26, 2013, at 7:04 PM, Dave Taht wrote: > Apenwarr has developed a really unique tool for seeing latency and > packet loss via javascript. I had no idea this was possible: >=20 > http://apenwarr.ca/log/?m=3D201304#26 >=20 >=20 >=20 > --=20 > Dave T=E4ht >=20 > Fixing bufferbloat with cerowrt: = http://www.teklibre.com/cerowrt/subscribe.html > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat