From owner-freebsd-hackers Sat Jun 28 21:13:03 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id VAA16494 for hackers-outgoing; Sat, 28 Jun 1997 21:13:03 -0700 (PDT) Received: from sendero-ppp.i-connect.net (sendero-ppp.i-Connect.Net [206.190.143.100]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id VAA16472 for ; Sat, 28 Jun 1997 21:12:46 -0700 (PDT) Received: (qmail 26677 invoked by uid 1000); 29 Jun 1997 03:57:08 -0000 Message-ID: X-Mailer: XFMail 1.2-alpha [p0] on FreeBSD Content-Type: text/plain; charset=iso-8859-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <199706281353.XAA30041@godzilla.zeta.org.au> Date: Sat, 28 Jun 1997 20:57:08 -0700 (PDT) Organization: Atlas Telecom From: Simon Shapiro To: Bruce Evans Subject: Re: Clists limited to 1024 bytes? Cc: bmcgover@cisco.com, hackers@FreeBSD.ORG Sender: owner-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Hi Bruce Evans; On 28-Jun-97 you wrote: ... Thanx for an excellent technical review. This type of posting is very useful. > Anyway, 19200 bps is not a heavy load unless there are a lot of active > ports. With 32 active 16550 ports it would be fairly heavy, but still > gives less than 6% of the throughput of a single 10Mb/s ethernet. I was thinking more (on a 16550) about what happens at 115,200, 230,400, and more. These are speeds we see already today with ISDN lines. The option of an external TA (such as a Motorola BitSRFR) is very apealing, but behavior at these speeds needs careful consideration. How would you adjust the drivers to acomodate these speeds? We experienced a lot of complex problems with SCSI transactions until we bumped the sio interrupt bufferto double its size. While performance (on the sio ports - we use them only for PPP) did not drop visibly, the strange incidence of dropping biodone() calls virtually stopped. Simon