I was playing with the Gizmo5 service today- we’ve had a few customer now ask if they could have Fonolo call them back at their Gizmo5 address, instead of a regular PSTN number. Their service, which is very Skype-ish, aims as providing cost saving on international phone calls, as well as provides free calls between Gizmo5 users.

One of the first things I noticed (after installing the Gizmo5 client), was that their system allocates each user a “SIP” number, which they made the unfortunate choice of formatting like a standard ten digit phone number (XXX-YYY-ZZZZ)- not only that, but they used the area code 747!

Unfortunately, they don’t have any stake in the *real* 747 area code controlled through NANPA– even worst, looking at the NANPA database, the 747 area code is already allocated as an overlay to the 818 area code (in California), and is set to be put in service May 18th, 2009 (~3 months from now).

Now, the Gizmo5 site doesn’t seem to make any mention of this, and there are only a few posts out there I can find- but they all simply say that the “SIP number” was never meant to be used as a normal PSTN number- it can only be called from one client to another, or as a full SIP address (by tacking on @proxy01.sipphone.com)- if that’s the case, it seems really weird that they opted to use phone numbers, instead of just usernames.

I’m not sure how they plan to handle it when *real* PSTN numbers in the 747 area code start getting allocated to people in California, and then one of their users with a DialOut package tries to call one of them? I’m sure it’s not going to take long before phone numbers start being duplicated, and they’re going to have to solve this issue.

Not to mention general confusion; I’ve read post after post about people being confused about why they can’t dial their 747 phone number from PSTN number.

As far as Fonolo support, I was hoping to simply trunk any calls to the 747 area code over SIP to the Gizmo5 system, as if they were just regular phone numbers; in testing, it seems to work well, but I’d just run into the same issue they will, come May.

I’ll have to just add them into the system as generic SIP addresses- hopefully I’ll have this working soon.