[ale] Huge number of PPP connections

[JANINDRA at MS.NDCORP.COM]

If it matters, the ever popular, hometown, national Internet provider,
Mindspring uses Linux boxes for their services. I think that should be
testament enough to the "stability" and ability. The tech support guys there
(or atleast the one I talked to) seem pretty open to sharing information.
Maybe they can help you with this quest.

--Randy

p.s. Of course you will have to share the info with us.

-----Original Message-----
 From: Joe Knapka [mailto:jknapka at charter.net]
Sent: Friday, September 17, 1999 10:44 AM
To: ale at ale.org
Subject: [ale] Huge number of PPP connections


Hey, folks,

A co-worker of mine is working on a project where he needs
to talk to a large number (hundreds) of remote field
devices over leased lines using PPP. He's wondering if Linux
would be an appropriate platform for a communication server.
The bandwidth requirements are low (probably 9600 bps
per channel), but the comms server *can't crash* - so he's
thinking that NT is right out. Normally we'd do this kind
of thing with VME boards running VxWorks, but there are
legacy/monetary issues involved here that preclude such
a solution.

I hope someone on this list can give us some pointers about
how (and whether) to do this. It's not too different in spirit
from running a dialup IP service, so maybe someone has done
something similar.

Specific questions are:

(1) We need at least 128 channels. Is it reasonable to expect
Linux to handle 128 PPP connections simultaneously? What
class of machine would be required? (I believe the answer is
"yes, a really fast one with a whole bunch of memory")

(2) How to even get 128 serial ports? We know the Digi EC/X
concentrator card will do it, but there doesn't seem to be
a Linux driver for that particular card. Are there
any alternatives? We might not mind adding more comms server
machines if necessary, but we'd like to do it all on
a single one if possible.

(3) What is the magnitude of development work likely to be
required? (I believe the answer is, "hardly any, once the
system is configured. Probably just write a chat script to
connect the field devices").

TIA,

-- Joe Knapka
* I speak only for myself, not for these idiots:
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