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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msunews!uwm.edu!news.moneng.mei.com!howland.reston.ans.net!gatech!newsfeed.pitt.edu!uunet!gator!tous!moses.oau.org!usenet From: jbh@moses.oau.org (James B. Huber) Newsgroups: comp.os.386bsd.questions Subject: Re: *BSD and 115kbps Serial Date: 05 Jan 1995 15:00:36 GMT Organization: Genesis Controls, Inc. Lines: 37 Message-ID: <JBH.95Jan5100037@moses.oau.org> References: <3eegop$3r9@homer.alpha.net> NNTP-Posting-Host: moses.oau.org In-reply-to: Podyss@quaestus.com's message of 4 Jan 1995 16:01:29 GMT >>>>> "Podyss" == Podyss <Podyss@quaestus.com> writes: Pod> I'm looking at linking a small group of remote PCs to a central Pod> site via ISDN. One of the remote PCs will be running FreeBSD, and Pod> it appears that the cheapest way to accomplish the link using existing Pod> equipment is to use asynchronous serial ISDN TA's on both ends. There Pod> is a Livingston Portmaster at the central site that has 115kbps serial Pod> ports. Using either the Accessworks QuickRemote TA or an Adtran ISU 128 Pod> will produce a 115kbps async connection using two "B channels", or so I'm Pod> told. Pod> So, the question is whether the machine running FreeBSD, assuming it has Pod> a serial port with a 16550 UART, can really handle a full 115kbps serial link. Pod> I'd use it as a router in this case. Does anyone have first hand experience with Pod> any kind of real, sustained, 115kbps serial connections in FreeBSD (or NetBSD or Pod> BSDI BDS/OS)? Can't speak for FreeBSD, I run BSDI ver. 1.1 I've been complaining bitterly about how bad the serial performance is. It is NOT capable of running 38.4k with 16550's. It silo overflows all over the place, the only option for me was to hack the driver myself. I've got it to run 38.4k now, but BSDI won't bless it. Not only that, they aren't going to fix it either. It still isn't up to 57.6k, it appears that the interrupt latency on the O/S is disgustingly high. Perhaps their version 2.0 will improve it, perhaps FreeBSD is better. The other options are either 'intelligent' serial cards, or 'semi-intelligent' cards. The 'semi-intelligent' cards can be had for around $200.00 (for 4 ports). Jim -- ====================================================================== James B. Huber jbh@moses.oau.org (Work) Voice (407) 662-7468 Genesis Controls, Inc. (Home) Voice (407) 679-2270 ======================================================================