Mark Townsley is a Cisco Fellow currently focused on the challenges of IPv4 address exhaustion and IPv6 deployment. Mark has over 20 years experience as a software engineer, joining Cisco from IBM in 1997. Mark’s first task at Cisco was the implementation of L2TP in Cisco’s IOS, as well as the scaling of virtual interfaces in IOS to support the new challenges of large-scale dialup and broadband deployment. Mark has authored a number of IETF RFCs including the L2TP specification itself (RFC 2661), served as co-chair of the IETF L2TP Extensions Working Group, Technical Advisor to the IETF PWE3 Working Group, and two terms as IETF Internet Area Director and member of the IESG as well as IESG liaison to the Internet Architecture Board (IAB).
As Internet Area Director, Mark was responsible for the standardization of a number of Internet protocols, including IPv6, DNS, MPLS VPNs, Pseudowires, DHCP, PPP, L2TP, and Mobile IP, among others. Mark earned his BS in Electrical Engineering from Auburn University and MS in Computer Science from Johns Hopkins University. He also teaches part-time at École Polytechnique. When not traveling, Mark lives with his wife and family in Paris, France.