I got a call from this same number (2227) Tried calling back and I got a all circuits are busy message. After doing a reverse look up I found out that it was a landline located around the corner of S Kinney Ave and E Locust St. I'm not sure what is there but I'll find out soon.
Got a call from this number. I get a couple different messages when I try to call back. One says, "All circuits are busy. Please try your call again later." The other says, "The number you are trying to reach is not a working number." So, I'm guessing it's used for outbound calls only, and they didn't leave a message so I have no idea what CMU department it is.
I just got a call tonight from this number while I was talking to someone else on the phone. They left no voicemail, so I have no idea who it might be.