Called our science lab 4 times in quick succession at 11am EST. I wasn't here, and the answering machine just got messages full of beeps for a long time.

Called my cell phone 4 times in 10 minute span, nothing but beeps on the other end. Tried to call the number back, but calls either weren't completed or got busy signal.

CALLED 30 MINUITES STRAIGHT BACK TO BACK...IN THE MIDDLE OF THE MORNING STARTING @ 3 AM.

This caller is calling every two minutes,  it seems to be an auto-dialer for a fax machine. I can hear the acknowledgment tones when I answer the phone. Calling the number back results in a busy signal confirming that the line is in constant use. I have reported the number to the national do not call registry and encourage you to do the same. https://www.donotcall.gov/complaint/complaintcheck.aspx

repeated calls to my cell phone.  sounds like a fax machine - beeps only on the other end.