SWB cable and sshd

[Jack]

Greetings,

I am looking for help on how to get ssh working for a
client. I recently converted a client over to Linux
for one of his computers. I have ssh running on his
machine, but things are not the way they should be.

Here's the thing, the computer is using a private ip
address. So in order to find out what his ip address
was, I connected from his machine to one of mine, thus
capturing the ip address in my logs (sure I know there
are other ways).

So, when I try to connect from my machine, to his I
get connection refused. While I can ping his box, and
it
appears to be up, neither ssh nor telnet work. I
didn't really expect telnet to work. Is there
something that
SWB does to prevent this? Or could his modem be
rejecting ssh? Another possibility I can think of is,
when I installed Ubuntu on his machine it installed a
firewall.

Anyone?

Thanks, 
Brian JD