about us

David Endler is the director of security research for 3Com's security division, TippingPoint. In this role, he oversees 3Com's internal product security testing, VoIP security center, and TippingPoint’s vulnerability research teams. Endler is also the chairman and founder of the industry group Voice over IP Security Alliance (VOIPSA). Previously, he has performed security research working for Xerox Corporation, the National Security Agency, and Massachusetts Institute of Technology. Endler is the author of numerous articles and papers on computer security and holds a Masters degree in Computer Science from Tulane University.


Mark Collier is the CTO for SecureLogix Corporation. He is responsible for all product and services R&D for SecureLogix. Mr. Collier is currently performing research into Voice Over IP (VoIP) vulnerabilities, with a focus on issues with the Session Initiation Protocol (SIP). He is a frequent author and presenter on the topic of VoIP security. Mr. Collier has been working in the security and telecommunications industry for over 10 years. Mr. Collier was previously with Southwest Research Institute, where he conducted research in a variety of areas, including information warfare and security. He holds a Bachelor of Science degree in Computer Science from St. Mary’s University.