I signed up with VoIP from Vonage since their prices were significantly cheaper and it seemed like a quality service.
While I still had Vonage, I obtained a Belkin wireless N-draft router. I wasn't aware of the interference issues that wireless routers have with 2.4gHz phones, so, at the time of switching to VoIP, I purchased a 6.0 DECT phone.
After switching to VoIP, I've had nothing but problems. Callers can't hear my voice and vice versa, call quality is very choppy, and on top if that, the only customer service that VoIP has is through a public message board. They have a number to call, but from what I understand, it's automated only.
Anyway, I worked out with one rep ports to forward through which calls are made/received. This worked for a day or two, now it's back to its old tricks.
Please reference this page (http://forum.voip.com/viewtopic.php?pid=35096#p35096) for information on the steps I've already gone through. Might it not even be a port forwarding issue? Thanks
I've tried the modem -> phone adapter -> router. Please click the link in my original post to read the message board thread between myself and VoIP.

1 comment… read it below or add one
sounds to me that something is not setup correctly , because voip should not require port forwarding
from your cable modem you should be hooked to the vonage
modem ( not the router ) from the back of the vonage the ethernet cable should then go to the router then from the router to any pc