Date: Tue, 30 Jan 1996 11:01:55 +1000 (AEST) From: Greg Ungerer <gerg@stallion.oz.au> To: hackers@freebsd.org Cc: Greg Ungerer <gerg@stallion.oz.au> Subject: Re: Multi-Port Async Cards Message-ID: <9601301101.aa20450@cluster.stallion.oz.au>
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dennis wrote (hmmm, are these attributions right, sorry if not): >>On Sat, 27 Jan 1996, dennis wrote: >>> This scenario is frightening to me....although I think that you've >answered my >>> question......Its the final straw I think in making FreeBSD >>> marketable...obviously >>> the AST solution is unacceptable for a real ISP....I wonder why the cyclades >>> board >>> needs mgetty.....whats the major diff between getty and mgetty? >> >>Dennis, a real ISP buys a fine Terminal Server to handle several >>Modem lines. Something like a Livingston Portmaster isn't too >>expensive for a real ISP. >> >>Many Modem lines produce many Interrupts. Outsource this job to >>another piece of hardware as an Terminal server. Let FreeBSD be >>a good server machine for www an such. > >a good multiport card offloads the interrupts and produces block streams >of data. Thats why I asked the question. > >A "real" isp might use a portmaster....but many non-isps would like to >provide a small number of modem lines for corporate dial-in. Its a big >selling point for the O/S. > Well I know lots of real ISP's that don't use terminal servers, they use real intelligent mulitport boards. Boards that do offload everything, all serial interrupts, flow control and have large memory buffers (like 5K or 6K for each of RX and TX per port). These are not toy ISP's either they are serious players, some have more than 64 high speed modems per system. Let me back this up with some numbers, a Stallion EasyConnection 8/64 ISA (which is powered by a 25MHz 186 with 512K RAM) uses about 0.1% host CPU per kbyte output (test done on a commercial UNIX flavor, Pentium 90, 32M RAM). The EISA bus version of the board does even better (32 bit writes of data sure help). Don't get me wrong though, they are good for small ISP's as well :-) Seeya Gerg --------------------------------------------------------------------------- Greg Ungerer EMAIL: gerg@stallion.com Stallion Technologies Pty Ltd PHONE: +61 7 3270 4271 33 Woodstock Rd, Toowong, QLD 4066, Australia FAX: +61 7 3270 4245
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