Unwanted and illegal robocalls continue to be both one of the largest communications-related nuisances (particularly since many of us are home to get them all day…) and are commonly used to defraud victims using social security, warranty and other scams. Fighting these unwanted calls has proven to be hard and is likely to require a combination of approaches that may also hasten the end of the traditional circuit-switched public switched telephone network. I’ll describe why unwanted robocalls are probably harder to curtail than spam emails and what techniques may help. I’ll focus particularly on calling number authentication, standardized by the IETF and ATIS in the STIR and SHAKEN working groups. STIR/SHAKEN offer a good case study that protocol standards are necessary, but need to be augmented by additional organizational infrastructure and operational practices to be successful. However, calling number authentication combined with simple call filters may only offer a temporary respite from unwanted calls unless other holes in the call delivery chain are plugged that allow shady operators to place millions of calls.
Prof. Henning Schulzrinne, Levi Professor of Computer Science at Columbia University, received his Ph.D. from the University of Massachusetts in Amherst, Massachusetts. MTS at AT&T Bell Laboratories; associate department head at GMD-Fokus (Berlin), before joining the Computer Science and EE departments at Columbia University. He served as chair of Computer Science from 2004 to 2009 and as Engineering Fellow, Technical Advisor and Chief Technology Officer of the Federal Communications Commission (FCC) from 2010 until 2017.
Protocol standards co-developed by him, including RTP, RTSP and SIP, are now used by almost all Internet telephony and multimedia applications. Fellow of the ACM and IEEE.