I have a ZA (+27), and a UK (+44) telephone numbers. These numbers are available as an option for those that live outside of the US, and the calling rates are easier for them. These numbers are voice only lines, and available for those that need to reach me.
For those that will call either phone number, it will ring my SIP client on my smartphone. However, there maybe instances where I will only accept calls when home. In addition, while the numbers are available, one will need to consider the time difference. For those that will call one of these numbers, consider the fact that I live in US-EST, and have the same time zone as New York City, and Washington DC.