Google Voice Now Offers SIP Addresses For Calling Directly Over IP

Wouldn't it be great if you could call a Google Voice number directly via SIP? So that you could bypass the PSTN when calling a GV number and go directly over IP? With potentially all the advanced capabilities that could give? (wideband audio, video, etc.) It turns out that you now can!

UPDATE – Nov 13, 2012: Over a series of subsequent posts about Google Voice and SIP, it first seemed like this service was working… then it stopped… then it started… and then it stopped for some people and still worked for others. As of November 2012 the service is not working for me.

By way of a tweet from Aswath Rao (crediting @truvoip) today I learned that you could simply take your Google Voice number and append "@sip.voice.google.com" to get a perfectly working SIP URI that you could use with any SIP phone. I naturally tried it out with my own GV number using the SJphone SIP phone:

Googlevoice

The call worked great. I answered it on one of my other phones and the conversation was fine – both audio streams intact, etc.

YATE?

What's interesting to me here is that SJphone reports that the remote client is YATE, a.k.a. Yet Another Telephony Engine. Yate has been around for a while (the voip-info wiki has some history) but hasn't been as widely known as, say, Asterisk or FreeSwitch. I subsequently made several calls using the Blink softphone on my Mac and again could see in the SIP traces that YATE was receiving the call on the Google end.

Looking over at the Yate News page, I see this note with regard to the January 31, 2011, release 3.1 of Yate:

Yate client calls can use Google Voice service.

The Yate client is a soft client for both voice and IM and in looking at their tutorial on using the client with Google Voice it would appear that this is about using XMPP (Jabber) to connect from the client over to Google Voice (I'm guessing it is using Jingle, which has been supported for some time by Google Talk (which is different from Google Voice)).

So the Yate client support is really something different… but the key point here is that Google appears to have chosen Yate to use on the receiving end of SIP calls into a Google Voice number.

WHY A SIP ADDRESS MATTERS

For some of us who have had Google Voice numbers for quite some time (mine dates back to the pre-Google-acquisition GrandCentral days), it's always been a bit frustrating that the only way to call a GV number was through the good old PSTN. Particularly because the PSTN is so… well… limiting. When I've been building apps in Tropo or Voxeo's Evolution platform, I've wanted to route them to my GV number… and I have to do this via the PSTN side. No big deal on one level, but it's just inefficient. If the call is already all on the IP side, why not just keep it all IP!

As we're off building the future of communications over IP, I've wanted to include Google Voice into that mix.

Now we can!

At least… unofficially. Perhaps at some point Google will come out and formally promote this capability.

Once a GV account has a SIP address, we then have to wonder what else we will be able to do with it. Could I, for instance, use wideband audio to my GV number?

For that to work, of course, I'd need to be able to register a SIP device with my GV number, which I can't do… and is the other side of the frustration with Google Voice. (Or at least be able to give GV a SIP URI as one of the addresses to call when a call comes in.) But conceivably once that happens I would be able to receive wideband audio calls. Ditto making video calls…

The first step is getting a SIP address that is workable… we now seem to have that.

Kudos to Google to making this inbound SIP connectivity available… and I look forward to seeing what else they will do with regard to SIP.


UPDATE #1: No sooner had I published this post when I learned of Todd Vierling's post over the weekend, "So, Google Voice: SIP is actually coming? (…in some form)", which may in fact be where Aswath and Alok learned of this news.

Todd also points out a serious security issue (the guessability of 4-digit PINs) and points out another post of his raising excellent SIP interoperability questions.

Thanks, Todd, for finding that this functionality works and for writing about it!


UPDATE #2: Alok Saboo (@truvoip) also posted about Google Voice SIP addresses yesterday, providing a tutorial for how to call those SIP addresses for free using the Blink softphone.

UPDATE #3 – 3/8/2011: I've now seen multiple reports (like this one and several in the comments to this post) that these SIP addresses may not be working for all addresses. As of this morning at 8:30am US Eastern time, I am having no problem calling my own Google Voice number via SIP using SJphone as shown in this article. However, others seem to be having problems.

UPDATE #4 – 3/8/2011: Given that reports continue that people are unable to access Google Voice via SIP, I wrote a follow-on post linking to some of the reports: Did Google Hang Up On Calling Google Voice Via SIP?

If you found this post interesting or useful, please consider either:


28 thoughts on “Google Voice Now Offers SIP Addresses For Calling Directly Over IP

  1. Mjgraves

    I recall hearing about the PIN security issue long ago, not long after GV was launched. Shortly thereafter the access was removed. Lets hope that they tighten it up a little rather than just turning it off again.

  2. Karl Fife

    Wideband audio via a Google Voice number (whether bypassing the PSTN or not) will depend upon whether Google Voice decides to hang on to the media stream (likely) and whether their UA’s will ‘prefer’ a wideband voice codec.
    We’ve all long since been able dial Gizmo5 subscribers via SIP URI, but those calls have been neither wideband, nor ‘direct’. In other words not ‘media path optimized’ (read: not low latency). Gizmo5 has always held on to the media stream out there in the cloud (presumably for nat-traversal reasons), consequently a ‘simple’ local call might result in the call media (the audio itself) traveling all the way to California (and back), even if you live in Bar Harbor, ME. Such a call could experience latency of 200+ ms, which is not great, especially if you choose to redirect those calls to your mobile phone, adding yet more latency to the call.
    Hopefully Google will throw us a bone, and sip.voice.google.com will ‘prefer’ a wideband codec like g.722 instead of the ‘regular old’ PSTN quality g.711 voice coder. Maybe Google will throw us a full-on party and ‘prefer’ something even better! Can you say SIREN 14?

  3. Ronblaisdell.wordpress.com

    Unfortunately, I was really hoping this would work with Tropo – but I keep getting “we cannot complete your call, please try again” from the GV network (I watched the Tropo debugger, it was not on the Tropo Network.) — So it looks like this has not been activated for all accounts on GV yet — even though, like you Dan, I go back to the old “GrandCentral” days.

  4. Dan York

    Karl, yes, that’s very true about the path of the media stream, and yes, we could certainly dial Gizmo5 folks via SIP. I never did any wideband testing with Gizmo5, so I wasn’t really tracking the media stream path. Thanks for passing along the info.
    And yes, it *would* be nice if Google would prefer one of the wideband codecs!

  5. Mjgraves

    In fact, Gizmo5 included an implementation of the GIPS codec set…including the wideband iSac codec that was once a feature of Skype. Since Google also bought GIPS perhaps there’s some hope that wideband might return…but I suspect that will be under the umbrella of GTalk and not Google Voice.

  6. Jason Goecke

    Ron, we looked again. While it was working this morning from Blink and Tropo, we have tried again and it looks like the service is not reliable on Google’s side. We have tried multiple combinations of Blink, Tropo and others to various GV numbers and it no longer works tonight.
    Seems others are having a similar issue in the Nerd Vittles comments here as well:
    http://nerdvittles.com/?p=725

  7. Dan York

    Brian, for SJphone I literally just typed the SIP address in the SJphone address window as I show above in the article. Just:
    sip:+1[GVnumber]@sip.voice.google.com
    That’s all you need to do. I don’t have X-Lite installed at the moment, but it’s the same idea there.
    Keep in mind that with SJphone, Blink, X-Lite, etc., all you can do is *call* a Google Voice number over SIP.
    You can’t register those softphones to *receive* calls that go into your Google Voice number. That is the part that continues to be missing from GV. Getting an inbound SIP address is just a first step toward better IP connectivity with Google Voice.

  8. TonyT

    Does anyone know the GV SIP settings for ATA devices? Whether it will work or not, I would like to just play around with them. Thanks
    PING:
    TITLE: The Fascinating Interest in Using Google Voice With SIP Addresses
    BLOG NAME: Disruptive Telephony
    Why are so many people interested in using Google Voice with SIP? Is this a sign that people really want to use SIP-based services for VoIP? Is this all hobbyists or people looking to play around with Google Voice? Or…
    PING:
    TITLE: Summary: Links to Posts on Calling Google Voice using SIP
    BLOG NAME: Disruptive Telephony
    Given that I’ll be the guest on today’s VUC call in about an hour discussing this topic, here’s a list of some of the posts involved in the recent saga around Google Voice and SIP. On Saturday, March 5, 2011,…
    PING:
    TITLE: Google Voice Via SIP – Not Dead Yet… (The Saga Continues)
    BLOG NAME: Disruptive Telephony
    So maybe calling into Google Voice via SIP isn’t as dead as I thought it was… multiple people have now left comments to my original posts indicating that they could call into their Google Voice number via SIP. And sure…
    PING:
    TITLE: Google Voice Via SIP – It’s Dead, Jim
    BLOG NAME: Disruptive Telephony
    So there it is… connecting to a Google Voice number via a SIP address no longer works for me, too. After I wrote on Monday about how you could connect to Google Voice numbers via a SIP URI, many folks…
    PING:
    TITLE: Did Google Hang Up On Calling Google Voice Via SIP?
    BLOG NAME: Disruptive Telephony
    Has Google killed the ability to call a Google Voice number via SIP that we just learned about in the past few days? My post yesterday seems to have resonated with many folks who rushed to try it… only to…
    PING:
    TITLE: Google Voice Supports SIP
    BLOG NAME: VoIP & Gadgets Blog
    We all heard the buzz surrounding Google killing off Gizmo5, including some peeved users like Todd Vierling. However, Todd Vierling then discovered that Google added SIP support to reach any Google Voice number. For instance, if you Google Voice number…

  9. offbeatmammal

    I just want a VoIP Google Voice application that works on Android, Phone7 and Windows PCs so I can stop paying for minutes I don’t use.
    Skype has apparently decided to abandon users (in the US at least) by forcing us to live with WiFi only so my loyalty is diminishing rapidally

  10. Todd

    As a point of info, considering I was one of the first to post about this ( http://goo.gl/KvTj8 ):
    It’s dead for me as of late yesterday evening. Calls from a few locations to any number (GV or not) are simply timing out.
    The hostname points to a more dynamic DNS record, voice-sip.l.google.com, which resolves to 74.125.155.192 from every location I’ve tried globally. So to those for whom it still works for you, congratulations! 🙂

  11. Dan York

    offbeatmammal, well, a mobile app for GV is a different beast than what we’re talking about here…. although the ability to call into a GV number using a SIP address would let you use any mobile SIP softphone (like CounterPath’s Bria) to call into a GV number. That only helps you call a GV number, though… not call other numbers via GV. For that to work, you would need to be able to register a SIP softphone with GV and then be able to make calls. That’s not supported now … and who knows when it might be.
    Not sure what you are referring to with regard to Skype. I’m in the US and use the Skype mobile app all the time over either WiFi or 3G… but then again, I’m using the *iPhone* app. I don’t know about how it works on Android or Windows Phone 7.

  12. Dan York

    Todd, Thanks for the info – and thanks for your great post which started all of this! Yes, I’m seeing lots of folks on Twitter and other places saying that it either never worked for them or has stopped working for them. It’s still working perfectly fine for me.
    Just to be sure there wasn’t an issue with only *my* GV number working, I called a friend of mine’s GV number using the SIP address and again it worked perfectly fine. We spoke for about 15 minutes and the audio quality was fine. Now, my friend is unable to call a GV number via SIP (including his own GV number), but I could call him fine.
    To help debug, I’ll mention that I’m using the very bare bones SJphone softphone. It’s NOT registered with any SIP server/proxy…. it’s merely making direct SIP-to-SIP calls. It’s running on an iMac, and my ISP is Time Warner cable.

  13. marko

    I have all IP mobile phone with SIP address from voxcorp.net and i call to anywhere works great.My mobile IP number is something like this sip:561202xxxx@sip.voxcorp.net

  14. Joeflyde

    Just tried to call my softphone on my Nokia N800 and was not successful. I sure hope this is functionality Google will allow.

  15. jack

    has anyone tried out the GrooVe IP app by snrb labs. I purchased the app, and the outbounc calls work fine, but I am unable to receive incoming calls.

  16. Justin Goldberg

    This allows people to call YOU through your SIP URI for free, and it will ring your PSTN phones and Google Talk. You can place free calls with the pauses and 2, but you can’t register a softphone.

  17. Dave Rosengarden

    Justin,
    Are you still seeing this solution work?
    What about the following:
    I have an IPKall number.
    I enter certain ‘SIP credentials’ in the IPKall set up page.
    Whoever dials that DID phone number provided by IPKall then forwards the call to my Google Voice account.
    Of course all my attached Google Voice phones ring (Google Talk, and any/all PSTN phones connected)
    Would this work?
    Thanks.

  18. Gavin Stevens

    It is standard behavior for SIP to alert your softphone (or phones) when you initiate a SIP invite request. Once you have answered the call on a device (the originator call) your call can be placed to the number you requested.

  19. John CG

    It was a cute idea to run your personal communication using the appended @voice.google.com address , until 5 years later we all get sick and tired of the word “google”. It is a sickening word, really, by today’s standard. Same with all the other provider’s names when you say it every day for 5 years. @facebook.com, @Whatsapp.com , @facetime.com , @skype.com , any word at all.
    Why is the old PSTN number so enduring? It is the linguistics , or the lack of. Words change over the course of history. A complete slang word “awful” just 50 years ago, is a complete legitimate word today. And it will fade into oblivion in no time.
    What else changes over time? Politics, country boundaries, demographics, population health, people’s height, people’s skintones, people’s colors, people’s race. Nothing lasts as long as you think.
    Good school works, hard works, intelligence, perseverance, health, strong will, these human spirits trascend boundaries of nations, races. Numbers are in the league as those good quality and are pure concepts and are much more enduring.

  20. Matthew

    SIP may not connect, but at least Inum should. I think people need to send feedback to Google Voice from their Accounts Page, and complain about Inum calls being charged 5c/min. They should be free, it is free for Google to connect, there is no gateway involved.

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