Same phone number U.S. or China

When I first traveled abroad in 1990 it cost about $5 per minute to place a call in Spain to the United States. 20 years later in China I have the same telephone number as in the U.S. for my landline. We use Voice Over IP - so anywhere there is an internet connection I can plug in my phone. It sounds just like it does in the United States, and I make telephone calls just like I would in the U.S.....so when I am dialing in China from China it is still an international call. I get free international calls. For my Chinese cell phone I just signed up for a Skype phone number and have all of my calls forwarded to my cell phone. It is wonderful. The drawback is that I cannot initiate calls on my cell phone. Which is a major bummer.