Bill Simon’s Free SIP-to-XMPP Gateway Easily Puts Google Voice on Your VoIP Phone

Unless you’re an adventurous VoIP tinkerer, there is no easy do-it-yourself approach to getting Google Voice to work over an IP phone’s unused line.

Obihai Technologies series of Obi telephone adaptors allow you to easily use a basic analog phone with Google Voice, but some contortion is required to use an Obi with an IP phone, and even then it may not work. You can follow our guide to rigging an OBi together with Cisco SPA-series IP phones (or Polycom phones as Voxilla member “Priller” shows in the comments section to that story). This approach is cumbersome and will not work with many IP phones that do not allow non-credentialed device registration (such as CloudTC’s terrific Glass IP phone).

If you are very determined, you can set up a spare computer, install the open-source PBX Asterisk, add the necessary modules to use Google Voice, and then register your IP phone with Asterisk. But this is difficult, costly, energy inefficient, and, does not even work very well, as documented by the excellent Michigan Telephone blog.

There are other open source telephone server solutions, like FreeSwitch and Yet Another Telephone Engine (YATE), that work much better with Google Voice but are even more difficult to install and maintain.

But don’t give up. There is actually a very easy way to get Google Voice on your IP phone that doesn’t require additional dedicated hardware.

Linux and telephony consultant Bill Simon was looking for a way to personally make phone calls over Google Voice using gear he already had, and customized a version of YATE to work with Google Voice. It worked well and Simon decided to offer access to his cloud-based server to others looking for similar functionality. The result: Simon Telephonics Google Voice Gateway.

Simon says the gateway now has more than 500 users and all voice data travels through his server “because at this time Google’s XMPP/Jingle extension does not permit an RTP bypass/reinvite sort of scheme.”

“The bandwidth usage is not insignificant but is not overwhelming, yet,” said Simon. “I am considering future growth options, but it would be best to work out an RTP bypass method or wait for Google to implement it.”

In the meantime, Simon is hoping to support the service entirely through small voluntary donations (suggested donation is $5/line per quarter). “If donations dry up and I need to move it to a subscription service, anyone who has donated will be given credit in that scheme,” he said. “But out of a spirit of optimism, I am giving the donation model a solid chance first.”

Getting Simon’s Google Voice Gateway is quite easy and fully detailed in a tutorial on the site. A user sets up a SIP account with the service and enters his or her Google Voice account information. The gateway attempts to negotiate contact with Google Voice with the account information entered and, if successful, the user is sent the credentials (server address, username and password) required to register an IP device with the gateway.

Simon says a user’s Google Voice information is necessary for the service to work, but the information is not stored on a web server or database.

If you are queasy about sharing your Google credentials with a third party, you should probably consider setting up Google Voice on an account separate from your main Google account. Giving your Google Voice it’s own little space on planet Google is significantly more secure than adding the service to the same account you email with, chat on, work on Google Docs on, etc. Plus, Google Voice on any external IP device works marginally better when it doesn’t have to share computer ticks with Google’s other services.

Also, a bit of tinkering is required on the Google side. To use Simon’s gateway, the Google Voice subscriber must log in to Gmail chat and place a phone call through a widget on the page. After a successful phone call through Google Chat, the user must select Google Chat as the destination for call forwarding in the the Google Voice settings.

We tested Simon’s Google Voice Gateway on a spare line on an Android-based CloudTC Glass phone and initially ran into a bit of a snag registering with the network. By adding more ports to his gateway to access Google Voice, Simon solved the problem. “I am going to add some logic soon that attempts multiple XMPP ports before giving up,” he said, pointing out that both Google Voice and his gateway are works in progress, both still in beta.

“It is not possible to set up a production level service against something that is changing and in beta perpetually, even if it is from the giant Google,” he said.

Once the initial registration wrinkle was ironed out, the service worked remarkably well. Voice quality was almost on par to that offered by a $75 OBi202. The addition of additional voice hops through Simon’s server located in the Chicago area introduced a bit of latency to calls, but not enough to affect a typical telephone conversation.

Configuring Google Voice and accessing voice mail through the phone is a breeze: Dial 1186 and you’re in.

Though not as robust as an Obihai adaptor or a full-fledged dedicated voice server, Simon Telephonics Google Voice Gateway is an excellent home solution for all but the heaviest users of Google Voice services.


  1. jstapleton says:

    So, all voice data travels through his server AND he needs your Google Voice account information. Anyone thinking about the security implications?

  2. Teodh4 says:

    Look’s like someone else just rolled out a Google Voice to SIP Gateway
    It’s not free, but simon isn’t taking any registrations right now either… I found a code at Web Hosting Talk: WHT4GV It’s $2/mo for the life of the account. I may signup for one today… 🙂 I’ve had it with asterisk’s google voice support >_<

  3. wardmundy says:

    Thanks to Bill Simon and YATE in a Flash, you now can also roll your own SIP-to-GoogleVoice Gateway in about 30 minutes.

  4. Sunil Shrestha says:

    Bill Simon Thanks a lot.


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