I have to say, I am impresssed. Keep up the good work. I also appreciate the SIP standard Gizmo Project uses. Open standards are very important and they allow interoperability with other services. It also allows for any application to connect to the service, which is important for cases where an application is not available or feasible in a particular situation, or in cases like mine where an alternative client application is preferable, but the same service quality is desired.

And congratulations for your accomplishments. For those who don’t know, Michael Robertson founded Linspire/Lindows, MP3.com, and MP3Tunes (no-DRM ) in addition to SIPphone/Gizmo Project.

Admittedly, I do not use the Gizmo Project application. I prefer to use Ekiga as well as Ekiga.net (although I do have an SIPPhone/Gimzo Project) account.

So I made calls to 0101*@proxy01.sipphone.com and was very impressed. It’s a very interesting system and the quality is great. I assume the call is not free for the person called (in this case a Nextel cell phone user) and also that the Caller ID number generated costs the cell phone user the same amount as any other number to call (it is not a free call for them). Correct me if I am wrong.

Any plans to connect to AT&T networks (specifically cell phones). That would really tap in to a lot of people, as there are many people who have Cingular/AT&T Wireless (as well as the fact that the other major wireless carriers have already joined the system).

It’s a great service and I hope it succeeds and grows over time. Good luck and thanks.

Here’s another fact about Backdoor Dialing. We implemented an advanced feature for all calls which is automatic assignment of a call back number. Lets say someone calls you through Backdoor Dialing. On your handset you will see a CallerID number assigned to them – even though they are calling you from a non-traditional phone (wifi phone, PC). They do not have to pay for this telephone number – it is automatically assigned. If you call it from your mobile it will ring whatever account called you. Normally people have to pay for a Callin or SkypeIn number to receive calls on VOIP devices. But we designed a system where the telephone numbers can be shared and we keep track of called number pairings to be able to route the call to the right place. To put this another way we know the ID of the person who called you. So when you call that number back we know who you are trying to reach.

We launched this in our Labs section because we’re doing several new call flow techniques here so it’s going to be interesting to see the user response.

Feel free to email me offline if you have any non-public comments you want to share.

– MR

Backdoor Dialing is an innovative program because it links voip networks of traditional carriers and pure voip companies completely bypassing the PSTN.

For consumers it really is about cost savings. Even on your mobile phone you are probably paying 10 cents per minute or more per minute. But it really is beneficial for international callers or heavy callers. The call quality is great. I hope you will try it.

– mr