Over WiFi, all of this does not involve your carrier, goes entirely over the Internet, and can be done WITHOUT a SIM card or a calling plan subscription in the case of CDMA. Basically, this gives you a phone number, and unlimited calling in North America with a data-only plan, or even without any cell phone plan (as long as you have WIFI coverage). You also get call-waiting, caller ID, and Voice Mail totally free. You can imagine the possibilities!
If you plan to use this outside the United States, and you are in the States, set this up BEFORE you leave, as it makes setting up the Google Voice account easier. If you are outside the States, look for other guides that cover how to set up Google Voice from outside the USA (you need a US IP address).
As a prerequisite to this guide, you need to either follow my guide for getting a free Sipgate number OR follow my guide for getting a free IPKall number..
SETTING UP:
1) Sign up for a Google Voice account if you don't already have one.
2) Follow ONE of my guide for obtaining a Sipgate number OR guide for obtaining a free IPKall number. Make a note of your Sipgate or IPKall phone number. Let's call this your FW number.
(5 - 10 minutes)
3) Add and confirm your FW number in Google Voice, and tell Google Voice to forward to this number when it receives calls (important). If you've followed one of my two guides in step (2), then your phone is ready to receive the confirmation call from Google Voice (for your FW phone).
(3 - 5 minutes).
4) Download the Google Voice Callback FREE app by Xinlu from the Android market on your phone, and set it up with your Google Voice account. Please note that the official Google Voice application is not capable of doing what this guide describes. Once you launch GV Callback, you will need to go through a set-up process.
a) Enter your Google Voice username and password on the first screen.
b) For your callback number, from the list, select the "FW number" you set up in step (2) above.
c) On the third screen, select whether and when you want to do callback, and for your convenience, you can even add a homescreen shortcut to toggle callback.
d) Click "Done".
(2 - 3 minutes)
5) If you are using Sipdroid, optionally you can make Sipdroid use another ringtone in the advanced settings, in order to distinguish incoming SIP calls from incoming regular cell phone calls.
(0.5 - 1 minute)
NOTE: If you have a mobile data plan, you can tell Sipdroid, CSipSimple, and Linphone to connect even over your wireless provider's data plan (3G), but *beware of potentially very high data charges*, since voip can be very data intensive. In my personal tests, a high quality codec consumes about 1MB per minute.
TESTING YOUR SETUP:
1) Make sure that the built-in SIP, Sipdroid, CSipSimple or Linphone is registered to whichever service you picked in step (2) above. For the built-in SIP, it should read "Receiving calls" under your SIP accounts in Settings->Call settings->Accounts. For the other apps, you can check the top-left corner of your screen. For Sipdroid, there should be a green dot there. For CSipSimple, there is a black icon that has a phone handle and "ip" in it. For Linphone, there should be an orange icon there.
2) Now, we make sure Google Voice Callback FREE is forwarding to your FW number (see step 2) properly. First of all, make sure that in the Google Voice settings, you have disabled forwarding to your cell phone (Thanks for your comment, Kristin). Now, call your Google Voice number and see if your cellphone rings through the SIP application (for Sipdroid, the call icon should be teal in color, *not green*). If you performed step (5) above, you should also hear the different ringtone now. You can pick up the cell phone to make sure audio works both ways by talking to yourself (sounds crazy, I know!).
At this point if you are wondering why you did all of this, here it is. If you dial a number through GV Callback, which we installed in step (4) above, you get an alternative Dialer, Contacts, etc. To cut things short, let me outline how to make a free incoming and outgoing calls to the USA and Canada.
MAKING OUTGOING CALLS:
0) If you have installed the toggle widget on your desktop, flip it to enable Google Voice Callback.
1) Select a contact your contacts, and call that contact. If you haven't configured Google Voice Callback FREE to always do callback, you will be presented with a dialog asking you how to complete the action. Select "Use Google Voice Callback".
2) Instead of the expected outgoing call, you should receive an *incoming* call from your Google Voice number. This happens because we set the callback number in GV to your "FW number" in step (4) above. Pick up this incoming call.
3) At this point, Google Voice's servers call the contact that you selected and bridges the two calls (the one to you and the one to your contact).
RECEIVING INCOMING CALLS:
1) For the purposes of this guide, please make sure that in your settings, Google Voice is *only* forwarding to your FW number. When everything is working, you can experiment with forwarding to other numbers as well.
2) When you have data coverage, and your SIP application is able to receive calls to your FW number (see the guides in step 2), if somebody calls your Google Voice number, you will receive the call through SIP, through data, free of charge, daytime minutes, roaming or any other such nonsense.
If using WiFi, don't forget to stay within wifi coverage during a call, since the incoming call is coming over the Internet. Most importantly, this works with your SIM card removed, or with a SIM card from any country in your phone! Try it if you don't believe it!
Long distance to destinations other than USA and Canada will charge your Google Voice credit, which can be recharged any time. Also, the Google Voice rates to worldwide destinations can be accessed by clicking "Rates" near where your balance is displayed in your Google Voice account (lower left).
This guide should work even if you are outside USA, as long as you already have your Google Voice account set up. For users outside USA, use any one of hundreds of guides to set up your GV account.
Enjoy, and please post your experiences!
SETTING UP:
1) Sign up for a Google Voice account if you don't already have one.
2) Follow ONE of my guide for obtaining a Sipgate number OR guide for obtaining a free IPKall number. Make a note of your Sipgate or IPKall phone number. Let's call this your FW number.
(5 - 10 minutes)
3) Add and confirm your FW number in Google Voice, and tell Google Voice to forward to this number when it receives calls (important). If you've followed one of my two guides in step (2), then your phone is ready to receive the confirmation call from Google Voice (for your FW phone).
(3 - 5 minutes).
4) Download the Google Voice Callback FREE app by Xinlu from the Android market on your phone, and set it up with your Google Voice account. Please note that the official Google Voice application is not capable of doing what this guide describes. Once you launch GV Callback, you will need to go through a set-up process.
a) Enter your Google Voice username and password on the first screen.
b) For your callback number, from the list, select the "FW number" you set up in step (2) above.
c) On the third screen, select whether and when you want to do callback, and for your convenience, you can even add a homescreen shortcut to toggle callback.
d) Click "Done".
(2 - 3 minutes)
5) If you are using Sipdroid, optionally you can make Sipdroid use another ringtone in the advanced settings, in order to distinguish incoming SIP calls from incoming regular cell phone calls.
(0.5 - 1 minute)
NOTE: If you have a mobile data plan, you can tell Sipdroid, CSipSimple, and Linphone to connect even over your wireless provider's data plan (3G), but *beware of potentially very high data charges*, since voip can be very data intensive. In my personal tests, a high quality codec consumes about 1MB per minute.
TESTING YOUR SETUP:
1) Make sure that the built-in SIP, Sipdroid, CSipSimple or Linphone is registered to whichever service you picked in step (2) above. For the built-in SIP, it should read "Receiving calls" under your SIP accounts in Settings->Call settings->Accounts. For the other apps, you can check the top-left corner of your screen. For Sipdroid, there should be a green dot there. For CSipSimple, there is a black icon that has a phone handle and "ip" in it. For Linphone, there should be an orange icon there.
2) Now, we make sure Google Voice Callback FREE is forwarding to your FW number (see step 2) properly. First of all, make sure that in the Google Voice settings, you have disabled forwarding to your cell phone (Thanks for your comment, Kristin). Now, call your Google Voice number and see if your cellphone rings through the SIP application (for Sipdroid, the call icon should be teal in color, *not green*). If you performed step (5) above, you should also hear the different ringtone now. You can pick up the cell phone to make sure audio works both ways by talking to yourself (sounds crazy, I know!).
At this point if you are wondering why you did all of this, here it is. If you dial a number through GV Callback, which we installed in step (4) above, you get an alternative Dialer, Contacts, etc. To cut things short, let me outline how to make a free incoming and outgoing calls to the USA and Canada.
MAKING OUTGOING CALLS:
0) If you have installed the toggle widget on your desktop, flip it to enable Google Voice Callback.
1) Select a contact your contacts, and call that contact. If you haven't configured Google Voice Callback FREE to always do callback, you will be presented with a dialog asking you how to complete the action. Select "Use Google Voice Callback".
2) Instead of the expected outgoing call, you should receive an *incoming* call from your Google Voice number. This happens because we set the callback number in GV to your "FW number" in step (4) above. Pick up this incoming call.
3) At this point, Google Voice's servers call the contact that you selected and bridges the two calls (the one to you and the one to your contact).
RECEIVING INCOMING CALLS:
1) For the purposes of this guide, please make sure that in your settings, Google Voice is *only* forwarding to your FW number. When everything is working, you can experiment with forwarding to other numbers as well.
2) When you have data coverage, and your SIP application is able to receive calls to your FW number (see the guides in step 2), if somebody calls your Google Voice number, you will receive the call through SIP, through data, free of charge, daytime minutes, roaming or any other such nonsense.
If using WiFi, don't forget to stay within wifi coverage during a call, since the incoming call is coming over the Internet. Most importantly, this works with your SIM card removed, or with a SIM card from any country in your phone! Try it if you don't believe it!
Long distance to destinations other than USA and Canada will charge your Google Voice credit, which can be recharged any time. Also, the Google Voice rates to worldwide destinations can be accessed by clicking "Rates" near where your balance is displayed in your Google Voice account (lower left).
This guide should work even if you are outside USA, as long as you already have your Google Voice account set up. For users outside USA, use any one of hundreds of guides to set up your GV account.
Enjoy, and please post your experiences!