Can't initiate a video conference from Mac to PC wtih iChat and AIM

Question

I am using iChat on an iMac intel core duo and trying to video chat with my dad on a PC laptop using AIM 5.9. We can both invite the other to video chat, however when either one click to accept various things keep us from initiating the chat. One message we get says a firewall may be the problem. My firewall is turned off. He is running Norton. But we tried with that firewall turned off as well as the windows firewall tirned off. At the moment we are on the same network connected via a 2wire router (Myself wirelessly and he via ehternet). I have tried various settings with the router firewall including setting the PC to DMZ and the Mac to the settings specified on portforwarding.com.
When I initiate the conversation from the Mac he gets a brief flicker like the video window is opening and then it closes; meanwhile my computer says waiting for response until it gives up. When he initiates the video chat and I accept I get the message that the chat failed because I did not respond even thougth I clicked accept. He gets a mesage that the chat failed and the reason may be a firewall.
Any ideas on how to get this to work so that we are able to video chat. Also he will be returning home in a few days and using a linksys router.
Any help or ideas to try would be great

Answer 1

Dear Ralph,
Sorry for the confusion, I did assume you were an Apple empoyee. Your knowledge about iChat is stunning. I appreciate your effort to help users by sharing your knowledge with such dedication. I do apologise.
Regarding:
Port forwarding is being automated and static ip addresses will be generated automatically.
Let's call it redirection (the handshake indicates the port to forward to).
When you have NAT running in your home you have the entire Internet available to all your machines. What if you have a machine behind the NAT gateway that needs to be accessed from outside? This is where redirection comes in. Redirection allows incoming traffic to be sent to a machine behind the NAT gateway.
An example:
rdr on tl0 proto tcp from any to any port 80 -> 192.168.1.20
This line redirects TCP port 80 (web server) traffic to a machine inside the network at 192.168.1.20. So, even though 192.168.1.20 is behind your gateway and inside your network, the outside world can access it.
The from any to any part of the above rdr line can be quite useful. If you know what addresses or subnets are supposed to have access to the web server at port 80, you can restrict them here:
rdr on tl0 proto tcp from 27.146.49.0/24 to any port 80 -> \
192.168.1.20
This will redirect only the specified subnet. Note this implies you can redirect different incoming hosts to different machines behind the gateway. This can be quite useful. For example, you could have users at remote sites access their own desktop computers using the same port and IP address on the gateway as long as you know the IP address they will be connecting from:
rdr on tl0 proto tcp from 27.146.49.14 to any port 80 -> \
192.168.1.20
rdr on tl0 proto tcp from 16.114.4.89 to any port 80 -> \
192.168.1.22
rdr on tl0 proto tcp from 24.2.74.178 to any port 80 -> \
192.168.1.23
A range of ports can also be redirected within the same rule:
rdr on tl0 proto tcp from any to any port 5000:5500 -> \
192.168.1.20
rdr on tl0 proto tcp from any to any port 5000:5500 -> \
192.168.1.20 port 6000
rdr on tl0 proto tcp from any to any port 5000:5500 -> \
192.168.1.20 port 7000:*
These examples show ports 5000 to 5500 inclusive being redirected to 192.168.1.20. In rule #1, port 5000 is redirected to 5000, 5001 to 5001, etc. In rule #2, the entire port range is redirected to port 6000. And in rule #3, port 5000 is redirected to 7000, 5001 to 7001, etc.
Static ip addresses are necissary to ensure that the router does not hand out the same ip twice, hence my question about the data transferred when a user connects his new mac to the one wich was set previously by the user (or other user). I think this information is explained in the Network Traffic Analysis you direct iChat to when they are asked to port forward (manually). I do not know the url by heart but it should be a known link to you.
Regarding auto response:
Sometimes you have to consider whether a very direct (and unelegant) interveniance in the software outweights the malfunction of an application that is causing a lot of trouble and inconvinience to Mac users. Personally I think that in this case the risk of being disturbed (still the same as anyone who askes for attention using chat or even phone) outweighs the much more irritating and incomprehensible "user did not respond" message and thus not being able to use one of the main features promised and promoted by Apple.
Yes life is inconsistent,
at least life is not sold to you.
Regards,
JPM