It sounds like you're running icamsource on multiple computers. Is that correct? If so, my personal experience is that it's better to use manual port forwarding. It's a task to set up, but it'll be rock-solid once you configure it correctly. Let's say you have 3 computers with the following local IP addresses: 192.168.1.10, 192.168.1.20, and 192.168.1.30
On each computer, you'll need to use the manual port forwarding registry file if on a Windows machine (
http://skjm.com/icam/iCamSourcePortForwarding.reg). I haven't done it on a Mac, so I'm not sure how that works. Then you'll need to use a different range of UDP ports for each computer...allowing 6 ports per camera (I think that's what they recommend). For example, let's say the computer ending in IP address 10 has 2 cameras, the one ending in 20 has 1 camera, and the one ending with 30 has 1 camera. On the computer ending in IP address 10, you'd want to forward UDP ports 12000-12011 (12 ports for 2 cameras). On the computer ending in IP address 20, you'd want to forward UDP ports 12012-12017 (6 ports for 1 camera). And on computer ending in IP address 30, you'd want to forward UDP ports 12018-12023 (6 ports for 1 camera). Now for the harder part...
You'll need to find the port forwarding section in your router settings. Depending on your router, entering the settings correctly (and in the correct place) could be really easy...or it could be a real pain. Make sure that you aren't entering this information as a virtual server setting or some other type of setting that looks similar to port forwarding. Using the same example IP addresses as above, this is the information you'd want to enter into the port forwarding section of your router:
Rule 1:
Private/local IP address: 192.168.1.10
Private/local ports: UDP ports 12000-12011
Public IP address: *.* (*.* means all IP address)
Public ports: same as private/local ports
Rule 2:
Private/local IP address: 192.168.1.20
Private/local ports: UDP ports 12012-12017
Public IP address: *.*
Public ports: same as private/local ports
Rule 3:
Private/local IP address: 192.168.1.30
Private/local ports: UDP ports 12018-12023
Public IP address: *.*
Public ports: same as private/local ports