From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail2.tohojo.dk (mail2.tohojo.dk [144.76.141.112]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 9128021F1A6 for ; Thu, 5 Dec 2013 15:43:22 -0800 (PST) X-Virus-Scanned: amavisd-new at example.com Sender: toke@toke.dk DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toke.dk; s=201310; t=1386286961; bh=yAiTVwy8n7J7L3nzaus9GHFUtStaXHq9++ddEExaxqo=; h=From:To:Cc:Subject:References:Date:In-Reply-To; b=Emsp3jUw9rwuP77D3E/FyfLLvMVfcikwXOF1nqEjUxb7LNa/lFOFozr8uBBDsmmBs PE7wd1RRpwPVsk9UuGVNcapfAMtspQDkD6njV2uVEBq7vL/tVDcUgBSGuh+jfLP2zE rf+fOZhdteHkAQ/f3//5ITT3nhBnCzLBWcKY9qbY= Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 6506DEF8B; Thu, 5 Dec 2013 23:43:29 +0000 (GMT) From: =?utf-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Dong Mo References: <269B8D3A-09C7-411E-9482-27CAA898A29F@gmail.com> <87ob4vau2z.fsf@toke.dk> <87fvq6c22z.fsf@toke.dk> Date: Thu, 05 Dec 2013 23:43:27 +0000 In-Reply-To: (Dong Mo's message of "Thu, 5 Dec 2013 17:28:44 -0600") Message-ID: <878uvyc19c.fsf@toke.dk> Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Cc: codel@lists.bufferbloat.net Subject: Re: [Codel] New to codel-- how to run codel on a linux box? 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: Thu, 05 Dec 2013 23:43:22 -0000 --=-=-= Content-Type: text/plain Dong Mo writes: > Thanks. My problem is solved. Excellent. Do share your results :) > It seems to me paping can sample for the RTT over this particular port, not the > whole connection setup time. Maybe it only record for the sync time but I am not > fully sure. From the latency result, it is quite close to RTT of the > link. Well, looking at the source code it seems to do a new connection each time: https://code.google.com/p/paping/source/browse/trunk/src/main.cpp#80 and https://code.google.com/p/paping/source/browse/trunk/src/socket.cpp#106 It seems to call connect(), then measure the time until select() returns with the socket ready to either read or write. Not sure when Linux considers a TCP socket to be ready, but I guess it's probably after receiving the SYN+ACK of connection setup, which would be one RTT after calling connect(), and would fit with what you're seeing. :) -Toke --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQEcBAEBCAAGBQJSoQ+fAAoJEENeEGz1+utPJaYH/2rWSU+i2zPJbImiFOZZP87e dBHc/qTDaQb29a6ln+7rZOgl0G07PO81KjqvnXx+/Z3Bd1GTxL6cxO5OBJ/tQHeC npBmF6LW00QfqHstvS7mOo17aHnF4t/ueIspzAnTQT+Kr7nC0DG6sv1Z77kKOBfW bp6JolxPIn6gN4cFLzNm3TW+J0uYZfyw1vMgNdY5p7Tx6eBt9NVQimkEGv8whJiU 6ZiC/nxM8sKNzOrsnCNFXJflbvpnRg2wNeONlLE2jKAFAy3TEM3LCFbZsD926vr+ kwMkFYwrLlviR4MvB8I6XIzS0caEkky+C6eVtESIESwRjtf4/PcHWjzAd0B8ZDQ= =MrXh -----END PGP SIGNATURE----- --=-=-=--