I have been playing with this VOIP setup for a while now, It works great! You need to be careful when you setup the remote extensions, why would I know that! Well I had some trouble when I started the installation over again to write a tutorial, I missed a step that really through me for a loop, and it was not anything to do with port forwarding, I set it up on two other routers. The problem I ran into was a password did not match for the remote extension, this will not happen again! There is some good information on the HSMM-Mesh web site on VOIP. I am planning on finishing a tutorial in the near future.