From owner-freebsd-current Mon Jun 12 20:02:19 1995 Return-Path: current-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id UAA19023 for current-outgoing; Mon, 12 Jun 1995 20:02:19 -0700 Received: from specgw.spec.co.jp (specgw.spec.co.jp [202.32.13.1]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id UAA18953 for ; Mon, 12 Jun 1995 20:02:13 -0700 Received: from tama3.spec.co.jp (tama3 [202.32.13.252]) by specgw.spec.co.jp (8.6.5/3.3Wb-SPEC) with SMTP id LAA26647; Tue, 13 Jun 1995 11:56:49 +0900 Message-Id: <9506130306.AA00040@tama3.spec.co.jp.spec.co.jp> Date: Tue, 13 Jun 1995 12:06:18 +0900 From: Atsushi Murai To: tom@uniserve.com Cc: current@FreeBSD.ORG Subject: Re: GENERIC kernel & some basic UNIX pointers In-Reply-To: X-Mailer: AL-Mail 0.94Beta Sender: current-owner@FreeBSD.ORG Precedence: bulk Tom Samplonius wrote: : :On Tue, 13 Jun 1995, Atsushi Murai wrote: : :> But Predictor-1 will try compression whole date when talk to peer ppp. :> This will give us two advantage as follows: :> :> 1. Decrese system over head due to reducing a sio H/W interruption. :> (H/W interruption is required big cpu time especially latest cpu) : : What about the extra CPU time and extra latency required for the actual :compression? Sorry I don't have data for handy but when I try to ping the other side which is running iij-ppp with the compression by ISDN TA, I can get a RTP around 50ms. :> 2. For ISDN TA that doen's has a own H/W compression can get double :> speed with not compression data. ( i.e. 38400bps -> 7KB/sec ) : : I've looked at this application myself. Especially over 56k or 64k :links. However, dedicated units still provide better performance (ex. :Gandalf 5250i with "advertised" compression up to 8:1, and in reality :isn't as much, but is still very good). Yes. it's could be. But point is most compression algorizum is protected by copyright. And each peer needs to accept(available) same compression for talking as *comunication*. At least there is no meaning "No open architecture" for communicat to world ;-) :Tom Atsushi. -- Atsushi Murai E-Mail: amurai@spec.co.jp SPEC Voice : +81-3-3833-5341 System Planning and Engineering Corp.