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Path: sserve!newshost.anu.edu.au!munnari.oz.au!spool.mu.edu!howland.reston.ans.net!news.sprintlink.net!sundog.tiac.net!rick From: rick@vox.trystero.com (Richard E. Nickle) Newsgroups: comp.os.386bsd.questions Subject: Re: *BSD and 115kbps Serial Date: 8 Jan 1995 15:41:00 GMT Organization: The Trystero System Lines: 40 Message-ID: <3ep12c$jt4@sundog.tiac.net> References: <3eegop$3r9@homer.alpha.net> NNTP-Posting-Host: vox.trystero.com In article <3eegop$3r9@homer.alpha.net>, <Dick@Seaman.Chenequa.WI.US> wrote: >So, the question is whether the machine running FreeBSD, assuming it has >a serial port with a 16550 UART, can really handle a full 115kbps serial link. >I'd use it as a router in this case. Does anyone have first hand experience with >any kind of real, sustained, 115kbps serial connections in FreeBSD (or NetBSD or >BSDI BDS/OS)? Yeah, I run my PPP connection to a USR Sportster (which has an NS16550 clone on it) at 115,200 24 hours a day. If only the phone line was so reliable. The system is a 486DX2/66, I don't know if I could get sustained 115,200 with my (other machine) 386DX40, because the modem on that one can only handle 57,600, but that box can handle 57,600 all day long too. I suspect that the 386DX40 can handle it (I *did* run a little testing with the Sportster when I first got the modem, but not for any long period of time, so I didn't see if it was dropping a lot of data or not, and the machine wasn't loaded). I think a machine slower than a 386DX40 might have trouble keeping up with all the interrupts. Oh, and if you want to, you can tweak the interrupt highwater marks in the driver, so that you can manipulate the 16 byte buffer the UART has (like, for instance, tuning it to interrupt less frequently on incoming stuff, and more frequently on outgoing stuff, actually, I might go look at this again today!). And yeah, it works great as a router, I use the 486DX2 to route for my local net (5 machines, two Unix, 2 OS/2, 1 Windows) through the PPP connection, and the 386DX40 routes for occasional dialup PPP/Slip connections from friends (OS/2 and Windows). All and all, FreeBSD will rock through all that, and I run Netrek on the thing and really suck up bandwidth and it still goes. (I don't think anything else will saturate a PPP line like Paradise Netrek). -- -- Richard Nickle http://www.trystero.com/rick.html