I have a VOIP adapter and a router, connected as: modem, VOIP, router.

I know it would be simpler to hang the voip adapter on the router; but, I've had some reliability problems with this arrangement.

How should I set up the port forwarding? Do I set it up in the adapter? In the router? Or, do both need to be set?

Al.......

For sure you need to do it in your router.
Regarding adapter, I don't know how it works.

For all forwarding and lowID issues see this website http://www.portforward.com/default.htm there is a talk through guide for setting up ports for every known router and programme.

1. Does the modem have a router built in? Some do; if so, you have to do port forwarding there as well.

2. Do portforwarding from modem to voip, then voip to router, then router to PC.