From owner-freebsd-questions@FreeBSD.ORG Tue Dec 10 19:49:21 2013 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id F1A73E83 for ; Tue, 10 Dec 2013 19:49:21 +0000 (UTC) Received: from st11p05mm-asmtp001.mac.com (st11p05mm-asmtp004.mac.com [17.172.108.249]) by mx1.freebsd.org (Postfix) with ESMTP id C78571A01 for ; Tue, 10 Dec 2013 19:49:21 +0000 (UTC) Received: from [17.168.91.184] (unknown [17.168.91.184]) by st11p05mm-asmtp001.mac.com (Oracle Communications Messaging Server 7u4-27.08(7.0.4.27.7) 64bit (built Aug 22 2013)) with ESMTPSA id <0MXL00EHYTM0CO70@st11p05mm-asmtp001.mac.com> for freebsd-questions@freebsd.org; Tue, 10 Dec 2013 18:49:14 +0000 (GMT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.11.87,1.0.14,0.0.0000 definitions=2013-12-10_06:2013-12-10,2013-12-10,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1308280000 definitions=main-1312100127 Content-type: text/plain; charset=us-ascii MIME-version: 1.0 (Mac OS X Mail 6.6 \(1510\)) Subject: Re: Round-trip time From: Charles Swiger In-reply-to: Date: Tue, 10 Dec 2013 10:49:12 -0800 Content-transfer-encoding: 7bit Message-id: <99B169BC-A941-400A-BD7F-97A98B173C19@mac.com> References: To: Anton Sayetsky X-Mailer: Apple Mail (2.1510) Cc: FreeBSD Questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Dec 2013 19:49:22 -0000 Hi-- On Dec 10, 2013, at 7:03 AM, Anton Sayetsky wrote: > What mechanism I can use to artificially increase RTT? I think that > dummynet is bad variant because I need 10 Gbit/s+ bandwidth. Well, _any_ mechanism you choose will need to buffer 10+ Gb/s times the extra latency you want to add. If you can't get dummynet or AltQ to serve the role adequately, and you've got a budget for a commercial alternative, a company called Shunra makes network appliances which can add 150ms of latency to a 10 Gb/s link for things like testing network communications between geographically separate datacenters or the like. Regards, -- -Chuck