I have a SIP VoIP service bundled with my ISP in Japan. This VSP "blocks incoming SIP calls from non-business partner external domains" (as SIP Broker so consisely puts it). The only people who can call me through this VoIP service for free are other subscribers, in Japan, with the same ISP, or one of their business-partners.
(Edited 2007-03-03: Further, for someone to call me for free through this service, they need to know that I have this "IP Phone" service, and they need to know my 050xxxxxxxx phone number.)
My ATA however, will accept incoming calls directly from anywhere on the internet (any IP address). So if the person that wants to call me knows my IP address (and 050 number), they can call my ATA direct, for free (no need to traverse my VSP's proxy).
For example, using the X-Ten lite softphone, if I set "Direct Dial IP" to "Yes" (default is "No"), and then dial,
050xxxxxxxx@xxx.xxx.xxx.xxx
(xxx.xxx.xxx.xxx = my IP address)
the call goes straight to my ATA at home and my home phone rings.
I then went to
www.e164.org, and set up an ENUM mapping. Both my home number (+8159xxxxxxx) and my VoIP number (+8150xxxxxxxx) are mapped to the SIP URI,
050xxxxxxxx@xxx.xxx.xxx.xxx
The test call at e164.org works fine, and using OzTell's "External free service" option in WebDialer also works (ie, using OzTell's webdialer, I dial my PSTN number, and the call comes arrives via VoIP). However, I haven't been able to get inbound calls to come in via SIP Broker, either using SIP Broker via VoIP, or using the SIP Broker PSTN gateway numbers.
So what I'm asking is, does SIP Broker / Voxalot work with Direct Dial IP?
Voxalot has a lot of configuration options - I was thinking maybe I could "call forward" my voxalot service to my IP address, or maybe I could setup my IP address as an external provider and transfer all calls there.
PS. It appears that my VSP blocks external SIP traffic at their routers. Hence, I can't register this VSP account to have it used with voxalot / OzTell webdialer etc.