PPS 6180...I need an answer, quick, please.

So, I live in Ottawa, Canada, and im trying to make a call to a buddy who lives in Georgia. I have his number and everything, but whenever I call it says: "the number you are trying to reach is unavailable, PPS 6180."
Basically, its not working and I need to get a hold of him. Can anyone tell me what causes this and how to potentially get around it? This has been happening for about a month and a half now. Is it possible that he changed his number?

Any help would be greatly appreciated. Thanks

Sounds like you're calling a cell phone.

If it's worth it to you, I'd try a reverse cell phone lookup to see if anything's happened to the line or whether he's taken up a new number. Intelius is running a sale on reverse phone lookup services now, so you can get one for cheap.