chances are, no VoIP provider will work right! until you get the initial problems resolved!
here is what I did, print this out, and follow the directions....
I have Packet8!
Connecting your voip adapter to your network to avoid issues:
1. Connect voip adapter to a vacant port on your existing network router/switch
2. Give your adapter a static IP address from your router/switch. i.e. for a Linksys wrt54gs router, assign the adapter a static IP address of 192.168.1.130, gateway will be 192.168.1.1 (That's the linksys IP address), subnet is 255.255.255.0 and the dns is whatever your isp uses. If you don't know it, you can use a dns from level 3. e.g. 4.2.2.1
3. Now, go into your router and look for the DMZ setting. Turn this on, and input the static IP address of the adapter you just made. e.g. 192.168.1.130
4. For those of you who are a bit more knowledgable of networking and MUST use ports instead of the DMZ, the ports for your VoIP are dynamic. They are ever changing. You will need to forward ports UDP 5060-65534 and TCP 8889
5. If after using VoIP, you realize that their is some echo or possibly 1 way conversation, or possibly that you are losing internet connection to your adapter, go back into the router and turn OFF any firewall or SPI settings. If this doesn't fix the problem, you might have to go back to factory defaults on the BPG510 and place it BEFORE your network router/switch. Placing a 310/410 adapter before the router is NOT an option
That is it. Now, the ports are all open to allow your adapter to work without any issues, HOPEFULLY. LOL!!!
Some notes: If using the BPG510 adapter, to make changes, connect a computer to it initially, and type in 192.168.88.1 then it will ask for a password. The password is "admin" without the quotes. Then change the WAN IP address to what it listed above as an example. You DON'T want to change the LAN IP address. Put in the static IP address in the range of your router like I suggested. When you connect it to the router and all is done, then a computer can be connected on a different port of the router, and still access the BPG510. Instead of the 192.168.88.1, it will be the new wan address you gave it. e.g. 192.168.1.130 . You still have the capability of connecting a computer directly to the lan port of the BPG510 and doing the 192.168.88.1 if you like.
If using the 310/410 adapters, there is no WAN settings. You would change the LAN settings for the IP address you want from your router.
good luck!!