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Newsgroups: comp.unix.bsd Path: sserve!manuel!munnari.oz.au!mips!decwrl!sdd.hp.com!wupost!uunet!newsgate.watson.ibm.com!yktnews!admin!w2chase From: cchase@watson.ibm.com (Craig Chase) Subject: (386BSD) Modems and com ports Message-ID: <1992Aug20.171557.30071@watson.ibm.com> Sender: w2chase@watson.ibm.com (Chase C) Date: Thu, 20 Aug 1992 17:15:57 GMT Disclaimer: This posting represents the poster's views, not necessarily those of IBM Nntp-Posting-Host: tweetie.watson.ibm.com Organization: Electrical Engineering, Cornell University, Ithaca NY Keywords: internal or external? Lines: 28 So, before I go plunk $250+ on a modem I wonder if someone could clarify the situation with dropped characters on a serial line. I understand that the 386BSD device drivers have trouble keeping up with high-speed serial communications, but how much trouble and how fast? The FAQ lists 38K bps as higher than you're likely to be able to go, does this mean the 19.2K would be OK with sl/ip? (BTW: 19.2K being MNP5 + V.32 and quite doable on a modem with V.32bis + V.42bis you can go up to 56K) My *real* question is, will it matter if I get an internal modem or an external modem? From a performance standpoint, it would seem that an internal modem has a little less hardware between the phone line and the bus, and so might have less trouble at the higher performance rates. But then, I tend to doubt that it makes any difference you could notice from a device driver. On the other side of the coin, an external modem could conceivably be hooked up to a smart (buffering?) serial card that might solve the dropped character problem altogether. Of course, external modems cost about $20-25 more... Any thoughts? Craig cchase@ee.cornell.edu