On Jun 24, blackbox@openface.ca wrote
> 
> Topic:  can an oldish PeeCee with a bunch of ISA ne2000s route with any real
> throughput? 
> 
> Ok, to summarize from the previous message thread:
> 
> - its cheaper to buy an ISA box full of $15 ethernet cards than a single
> quad-interface card
> - nobody has brought forward a quick and well-known software solution for
> monitoring IP byte counts on an ethernet network without using a whole whack
> of ethernet cards (as opposed to one interface, software monitoring packets
> and counting individual packets and bytes based on IP)
> 
> So my next step is to fill a PeeCee with cheapy ethernet cards.  Next issue;
> 
> How crappy is ISA?  Will, say, 5 ISA Ne2000s bring a 486/33 to its knees
> trying to deal with interrupts and such when under heavy network load?

Hum, if you have quite heavy network load on the 5 boards at a time you can
expect fifo overflow and packet loss. I'm seeing packet loss on a 486dx33 with
one 3c503 board.

> 
> I know its certainly possible to run such a configuration -- I'm currently
> doing so.  I have some old 486SLC/33 box with 5 Kingston NE2000 ISA cards in
> it, 2 subnets behind NAT, 2 subnets off my main internet default path, and
> then the default itself.  This seems to work nicely -- I boot from a floppy
> and I have a miminalist kernel that gets the machine going far enough to start
> routing packets -- I have an rc script that does ifconfig, ipf, ipnat, and a
> few routes, and thats it. 
> 
> Wirespeed throughput doesn't seem too hot on the machine I have.  For internet
> forwarded connections, its fine because of the relatively low speed of our
> internet link (T1), but when doing ftp/scp type stuff LAN to LAN, transfer
> rates tend to vary between 150kbytes/s to 500kbytes/s.  Other than that the
> machine has run well enough to support my office with minimal complaints for
> the last 10 months or so.
> 
> Ok so how about if we were talking about a Pentium 75Mhz-120Mhz, with PCI
> cards instead of ISA?  Would this help?  Is it still a bad idea?

With PCI boards things will be much better, if you take good bus-master capable
boards. I'm happy with my compaq Netelligent (TI ThunderLAN chip) and my DEC
clones, but I didn't test other PCI boards.
Also, for better performances take a PC with an external clock a 33Mhz.
That is, avoid the P75 and the P120, the P100 is the one wich will give the
best performances for this use.

I have here a router box which is a p200 with 4 ethernet board (a DEC, 2 NE2000
PCI and a 3c509 ISA), and I'm quite happy with it. As soon as we'll have an
RJ45 network, it will have 4 dual port Netelligent running at 100Mbs.
Let's see how it will run ...

--
Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
--