From owner-freebsd-hackers Sat Jan 5 10:57:32 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from ns.yogotech.com (ns.yogotech.com [206.127.123.66]) by hub.freebsd.org (Postfix) with ESMTP id 3BB3E37B419 for ; Sat, 5 Jan 2002 10:56:43 -0800 (PST) Received: from caddis.yogotech.com (caddis.yogotech.com [206.127.123.130]) by ns.yogotech.com (8.9.3/8.9.3) with ESMTP id LAA20413; Sat, 5 Jan 2002 11:55:54 -0700 (MST) (envelope-from nate@yogotech.com) Received: (from nate@localhost) by caddis.yogotech.com (8.11.6/8.11.6) id g05ItnR90527; Sat, 5 Jan 2002 11:55:49 -0700 (MST) (envelope-from nate) From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15415.19507.503984.613417@caddis.yogotech.com> Date: Sat, 5 Jan 2002 11:55:47 -0700 To: "M. Warner Losh" Cc: drwilco@drwilco.net, freebsd-hackers@FreeBSD.ORG Subject: Re: path_mtu_discovery In-Reply-To: <20020104.230218.17343558.imp@village.org> References: <5.1.0.14.0.20020105011402.01d75230@mail.drwilco.net> <20020104.230218.17343558.imp@village.org> X-Mailer: VM 6.96 under 21.1 (patch 14) "Cuyahoga Valley" XEmacs Lucid Reply-To: nate@yogotech.com (Nate Williams) Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > : Out of curiosity, where do MTUs < ~512 occur? > > Old slip links that used it to reduce latency. I suspect that there > aren't too many of them left in the world. You'd be suprised. I measure SLIP's effeciency (in throughput) to be about 5-15% more effecient than PPP in older versions of FreeBSD (both using kernel versions, slip and ppp). Since both were using static configurations on both ends and the only traffic was TCP/IP, there was no reason to use PPP over SLIP so we opted for using the more effecient protocol. I can imagine this is SLIP is still more effecient than PPP in terms of CPU, although I haven't measured it in years. Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message