From owner-cvs-all Wed Jul 17 21:15:44 2002 Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C475737B400; Wed, 17 Jul 2002 21:15:41 -0700 (PDT) Received: from thunderer.cnchost.com (thunderer.concentric.net [207.155.252.72]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7C72F43E42; Wed, 17 Jul 2002 21:15:41 -0700 (PDT) (envelope-from bakul@bitblocks.com) Received: from bitblocks.com (adsl-209-204-185-216.sonic.net [209.204.185.216]) by thunderer.cnchost.com id AAA17978; Thu, 18 Jul 2002 00:13:01 -0400 (EDT) [ConcentricHost SMTP Relay 1.14] Message-ID: <200207180413.AAA17978@thunderer.cnchost.com> To: Garrett Wollman Cc: "Greg 'groggy' Lehey" , cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: Retransmission timeouts (was: cvs commit: src/sys/netinet tcp_timer.h) In-reply-to: Your message of "Wed, 17 Jul 2002 23:18:08 EDT." <200207180318.g6I3I8hj000996@khavrinen.lcs.mit.edu> Date: Wed, 17 Jul 2002 21:13:00 -0700 From: Bakul Shah Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > I've found it: it's (obliquely) in the Allman and Paxson paper > referenced in the commit logs. Implementations are allowed to delay > ACKs for as long as 500 ms. RFC1122 section 4.2.3.2 says a TCP SHOULD implement delayed ACKs but the delay shouldn't be excessive and MUST be less than 0.5 seconds. In section 4.2.3.1 it also says that "The lower bound (of the RTO) SHOULD be measured in fractions of a second (to accommodate high speed LANs)". Though it is not the speed but the latency that matters. > Network speeds have practically nothing to do with a correct > implementation of the TCP protocol. I agree on the whole but IMHO "correct" is too strong a word. No reason TCP should stop evolving now. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message