Thank you very much for your reply, Henrik.
So a ulimit of 1000 ought to limit the total number
of connections to about 300+. Looks like under my
current 2.4 Linux kernel, maximum number of filedescriptors
possible is around 26K, but only 1024 allowed per process:

# sysctl fs.file-max
fs.file-max = 26208

# ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
file size (blocks, -f) unlimited
max locked memory (kbytes, -l) unlimited
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 2047
virtual memory (kbytes, -v) unlimited

-- Paul