iChatAV and Zoom X3 modem

[dobbin]

I have just set up my new iBook with my broadband ADSL connection using airport express and a Zoom X3 modem.

It works fine with mail, safari, and text chats using iChat. BUT.. I can't make video or audio chats work. I can get as far as issuing or receiving an invitation to chat, but then it says something like "the other user did not respond". My brother is getting similar messages at the other end.

I have turned off the OS X firewall, and so I think this is something to do with the firewall in the modem. I tried to disable that, open ports, and set up a DMZ or something, but I didn't really understand what I was doing, and couldn't get it to work.

Can anyone who has got this modem advise me on how to disable the firewall in easy steps please?

Thanks.

 

[dobbin]

OK, I followed the instructions on this page to set up my modem/router as a PPP half bridge(?). As far as I understand, I think this bypasses NAT and gives my iBook the same IP address as my sevice provider has sent to the router.

Video chatting is now possible using iChat which is what I was trying to achieve. However this doesn't seem to work with airport though, only when the router is plugged directly into the iBook. in fact I can't get any internet connection at all though airport with my modem set up like this. I think I need to set up the airport as another bridge to simply connect the modem/router to the iBook without having an IP address of its own. Is this possible? Am I going in the right direction?

I don't really understand what I'm doing, so any advice would be really appreciated.

 

[dobbin]