As we are seeing with VoIP call rules, SIP, and cell phones, modern telephony is becoming more about being able to reach a person than to reach a phone. What if you could have an international number, one that follows you everywhere in the world? This is the vision behind the “iNum initiative”.

The company behind the iNum initiative is Belgian telco Voxbone. Voxbone, founded in 2003, sells direct (DID/DDI) and toll-free telephone numbers, which are carried across their worldwide network of VoIP servers and PSTN switches. In 2008, Voxbone petitioned the International Telecommunication Union, which regulates global country codes and other standards, for an international area code.  The ITU granted Voxbone the global country code +833 5100. iNums are 15-digit telephone numbers assigned to no country. You could perhaps say that the +833 5100 area code belongs to the internet.

iNum is based on SIP standards. You can send voice, HD video, and txt over an iNum telephone number. It is possible to call an iNum in the format "sip:[email protected]". Ideally, all iNum calls would be free, much as SIP-to-SIP calls are free, but technological barriers and per-minute fees drive up the cost across certain carriers. Skype, Sprint USA, and Google all support iNum, but only Google (Talk and Voice) carries iNum calls for free. VoIP traffic can stay completely off the PSTN, and keep the cost at or near zero. Many VoIP providers give an iNum number as part of their service for free. Both PSTN and VoIP carriers can benefit financially from the added connectivity of iNum.

Additional Reading
– Direct Inward Dialing (DID)
– How Will SIP Trunking Help My Business?