Re: flexfax: How best use multiple modems?

[Matthias.Apitz@SOFTCON.de]

Nico Garcia wrote:
    
    On Wed, 5 Nov 1997, Karl Feichtinger wrote:
    
    > Hi,
    > 
    > I know this topic has been discussed earlier, however, I would be glad to
    > receive a specific advice. I want to connect 6 modems to a Linux machine. 
    > 
    > I wonder whether I should use internal modems (this reduces cabling) or
    > external modems, in which case I need a recommendation for a multi-port
    > serial board.
    > Which minimum RAM and Processor requirements would I need? SCSI?
    
    More than 2 modems can cause grief real fast. PC clones normally have
    only two interrupt codes for serial ports. You can't just add new ones
    willy-nilly, they're very much built into the hardware and the
    drivers.

As long as you have *free* interrupts (you may also use higher
interrupts like 10, 12, 14) you can add serial cards.
I've a 486 PC with 16 MByte RAM at home
which drives 4 serial ports with speeds up to 460.000 bps
without any kind of problem. The PC is running SVR4.2 and runs
a lot of other daemons: HylaFAX's daemons, innd, httpd, nnmaster...
    
    I suggest that for this many modems, you definitely need some sort of
    serial expander. Alternatively, there are several types of network
    ready multiple modem servers which might save you a lot of work and
    grief and be overall more reliable: you might then be able to use the
    Linux box to handle the fax service. I believe some people have done
    this on this group....
    
    			Nico Garcia
    			Engineer, CIRL 
    			Mass. Eye and Ear Infirmary
    			raoul@cirl.meei.harvard.edu

Modems connected to network servers will not work reliable with
HylaFAX because you can't control the time over a TCP/IP link
to match the T.30 timer demands.

	matthias