VoIP Cookbook: Introducing your country code to International VoIP network
If you want to introduce a PSTN or cellular number with a specific country code to this VoIP network, you can do so through menu available at http://www.e164.org/pstnadd.php. What you have to enter is the country of the PSTN or cellular number, area code, local telephone number, and the SIP account registered with a SIP provider where the PSTN numbers are those of SIP.
When registering the phone number, you need to have the phone ready to receive calls, as within 15 minutes after you registered it, e164.org will dial your number to provide you with a Personal Identification Number (PIN) required to activate the account. Write them down somewhere so you don't have to memorize them. Go back to the Web and activate your account using the pin that has just been given to you. Once this is completed, your PSTN (or cellular) number can be recognized in the VoIP network, with all the numbers registered with the network capable of dialing your SIP account using your PSTN numbers.