Google Voice/SIP gateway tutorial
Here’s how it works.
Setting up a new gateway
Step 1: fill out the form, following the prompts and reading the FAQ below for additional information. Then click the Add button.
Step 2: GVGW will test your account and then present SIP authentication and registration information that you will use to set up a SIP trunk to the gateway.
Deleting your Google Voice gateway
Step 1: fill out the form again, using the same information you filled in to add the gateway. Note: this time, you do not need to enter an e-mail address. Then click the Delete button.
Step 2: GVGW will confirm your configuration and proceed to log out the Google Voice user and delete the gateway registration.
Usage
Important: If you have never made a call through Google Voice before, you must first log into Gmail chat with your account and initiate a call through the chat widget. Then log into Google Voice, go to your voice settings and select Google Chat as the destination for call forwarding.
Configure a SIP trunk and register your system to the gateway address given in your Add confirmation. You could also just register a single hardware phone, softphone or ATA.
You will receive incoming calls over SIP to your Google Voice DID. To place calls, send your calls over the trunk using a full 11-digit (1-areacode-number) string for US calls. If you have credit on your Google Voice account and want to send international calls, use the full international dialing string starting with the country code.