The grandcentral dialer is not a Voice application. It merely enables the callback dialing that grandcentral provides.

If you go to the account tab on grandcentral dialer there should be a callback number. If it's blank you have a problem. That is the number where YOU are. The number you dial is who you want to talk to. When you hit dial GC will call you on YOUR number and then connects you with the number you dialed, you will hear ringing until the other end picks up the phone.

Here are a few things that show a problem.

1. The phone listed on the account page doesn't ring
2. When you pick up the callback phone you don't hear ringing
3. You are not connected to the number dialed.

If you wish to use the Nokia as a "phone" you also have to create a Gizmo project account and configure the a SIP account on the Nokia. This enables the VoIP functionality that is compatible with GC. You can then go to GC and setup another phone and set it to the Gizmo "1 (747) xxx-xxxx" account number.

Once that is done you can then go to the account tab under the dialer and pick the "1 (747) xxx-xxxx" number and the dialer will "call" the tablet.

There is more discussion in one of the older thread here. The dialer application will make the whole process easier once you are setup since you will be able to call ANY number, not just those in your phone book.