From owner-freebsd-questions Thu May 20 16: 9:39 1999 Delivered-To: freebsd-questions@freebsd.org Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (Postfix) with ESMTP id 11B5B1589A for ; Thu, 20 May 1999 16:09:31 -0700 (PDT) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id IAA14995; Fri, 21 May 1999 08:39:29 +0930 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.3/8.9.0) id IAA13602; Fri, 21 May 1999 08:39:29 +0930 (CST) Date: Fri, 21 May 1999 08:39:29 +0930 From: Greg Lehey To: Mark Tinguely Cc: brian@Awfulhak.org, questions@FreeBSD.ORG Subject: Re: Number of TUN devices Message-ID: <19990521083929.N89091@freebie.lemis.com> References: <199905201413.JAA28383@plains.NoDak.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i In-Reply-To: <199905201413.JAA28383@plains.NoDak.edu>; from Mark Tinguely on Thu, May 20, 1999 at 09:13:12AM -0500 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thursday, 20 May 1999 at 9:13:12 -0500, Mark Tinguely wrote: > FYI: > > I am playing with the idea of a direct-insert PPP for future SONET/ATM/DSL > PPP connections. here compression/ACCM are not a concern but higher data > rates make the kernel/user space copying (x2 once on each device inteface) > and the prcessing copying can be a concern for throughput. I am not bad > mouthing the tun driver; it is an excellent driver for serial devices that > needs to PROCESS the packets from/to the PPP link. > > In the SONET/ATM/DSL world, the PDUs will already be in mbufs from the > device driver. The MRU/MTU can be much larger. The data packets do not > need to compressed/encrypted/ACCM-ed, so the for those opened NCPs, the > data packets can be placed directly into the appropriate kernel protocol > stacks. the diagnostic, and control packets can still be processed in > user space via a protocol socket. > > Have you experimented what kind of through-put the NOS-TUN can handle? > I suspect that this model would be good enough for DSL speeds. Why are you thinking of using user PPP for this? As you say, at the data rates you're thinking of, it's not an optimal solution. This is also probably material for -hackers. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message