Path: utzoo!mnetor!uunet!husc6!think!ames!ptsfa!varian!kinetics!tim From: tim@kinetics.UUCP (Tim McCreery) Newsgroups: comp.protocols.appletalk Subject: Re: Kinetics Fastpath hardware bug Message-ID: <196@kinetics.UUCP> Date: 12 Dec 87 23:40:59 GMT References: <8712090036.AA02061@umd5.UMD.EDU> Reply-To: tim@kinetics.UUCP (Tim McCreery) Organization: Kinetics, Inc., Walnut Creek, CA. Lines: 33 I have not been keeping up with reading this newsgroup lately, but the recent item by Dan Magorian concerning FastPath definitely got my attention. Mostly, I want to clear up a few points with some facts. The "hardware bug", i. e. "misplaced capacator (sic)" is not quite correct. In different network environments, tranceivers, tranceiver cables, etc. inject different levels of noise into the gateway. There is a crystal oscillator circuit to the SIA (usually the AMD 7992) and the sensitivity to noise of the TCLK input to that SIA is also quite variable. Therefore, different units experience noise problems to lesser (i. e. not at all) or greater extent. Reduced noise sensitivity can be obtained by moving a capacitor closer to the serial interface chip, thereby reducing some of the common ground path near it. All current and future units from Kinetics are reducing noise sensitivity in this fashion. We recommend this capacitor movement change to all sites which are experiencing an intermittent failure problem which shows up as the boxes appear to hang (no RTMP packets are being sent), but then fully recover after a power cycle. I should note that most problems reported to us are not like this, but are due to configuration inconsistencies and this "fix" will not solve those problems. With respect to Microsoft, the implication in Dan's article is that ALL the units were failing several times per day. This is false. Because of the size of the Microsoft installation and their excellent network administration, they became an ideal site for diagnosing the problem as being unit and environment specific. We are grateful for their patience and assistance in helping us first document and then find this problem. We are in the process of writing a technical note concerning this problem and the fix and will be mailing it to all of our customers within the next week or so. tim