From owner-freebsd-isdn Thu Oct 1 06:36:18 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id GAA18352 for freebsd-isdn-outgoing; Thu, 1 Oct 1998 06:36:18 -0700 (PDT) (envelope-from owner-freebsd-isdn@FreeBSD.ORG) Received: from mail.aussie.org (hallam.lnk.telstra.net [139.130.54.166]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id GAA18341 for ; Thu, 1 Oct 1998 06:36:11 -0700 (PDT) (envelope-from mlnn4@oaks.com.au) Received: from bigbox (frankenputer.aussie.org [203.29.75.73]) by mail.aussie.org (8.9.0/8.9.0) with SMTP id XAA27382; Thu, 1 Oct 1998 23:35:51 +1000 (EST) Message-Id: <199810011335.XAA27382@mail.aussie.org> From: "Hallam Oaks P/L list account" To: "freebsd-isdn@FreeBSD.ORG" Cc: "Andrew Gordon" Date: Thu, 01 Oct 1998 23:36:23 +1000 Reply-To: "Hallam Oaks P/L list account" X-Mailer: PMMail 98 Standard (2.01.1600) For Windows NT (4.0.1381;3) MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Subject: Re: HSCX query Sender: owner-freebsd-isdn@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >software would use a lot of CPU. If there is hardware HDLC for the B >channels but not for the D channel, that would require just the same >development effort but would have a much less serious impact on >performance since the average data rate on the D channel is extremely >low. It may seem to unbelievable (but it's true) that it's the opposite way. There is hardware support for decoding the D channel but not for the B channels. As far as the software is concerned, the ASIC is transparent for the B's in that it just passes through whatever it receives from the ISAC. [Note that in my original message I said 'PCI ISAC', but this was a typo; I meant PCI ASIC. It does the PCI glue functions and also implements the D channel decoding etc. The ISAC is an ordinary Siemens PSB2186.] As there's a Linux driver for this card in existance the FreeBSD version should not (I hope) be a major problem to get working, but I am stepping carefully as I am not an experienced Unix device driver type person. -- Chris To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isdn" in the body of the message