From owner-cvs-sys Wed Dec 4 11:43:49 1996 Return-Path: owner-cvs-sys Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id LAA17905 for cvs-sys-outgoing; Wed, 4 Dec 1996 11:43:49 -0800 (PST) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id LAA17895; Wed, 4 Dec 1996 11:43:44 -0800 (PST) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id UAA12723; Wed, 4 Dec 1996 20:04:41 +0100 From: Luigi Rizzo Message-Id: <199612041904.UAA12723@labinfo.iet.unipi.it> Subject: Re: cvs commit: src/sys/net if_tun.h To: phk@critter.tfs.com (Poul-Henning Kamp) Date: Wed, 4 Dec 1996 20:04:40 +0100 (MET) Cc: fenner@parc.xerox.com, phk@freefall.freebsd.org, CVS-committers@freefall.freebsd.org, cvs-all@freefall.freebsd.org, cvs-sys@freefall.freebsd.org In-Reply-To: <4197.849725809@critter.tfs.com> from "Poul-Henning Kamp" at Dec 4, 96 07:56:30 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-cvs-sys@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > Sorry I misunderstood then. I thought it was the max allowed, not the > default MTU. > > Yes, this is backing out then. On this topic: the tun device is quite often used for PPP connections, which in turn end up into relatively slow modem lines. An MTU of 1500 perhaps makes compression and link usage a little bit more effective, but at the price of horrible interactive performance: an MTU-sized packet is about 0.5s at 28.8K. Wouldn't a default of 576 (or whatever is used for slip) more appropriate, given the typical use of tun ? The minority of users which use tun for Mbit/s communications are free to modify the MTU to suit their needs, I think defaults should be chosen to suit the majority of cases. Luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________