18th International workshop on
Network and Operating Systems Support
for Digital Audio and Video
Braunschweig, Germany    May 28-30, 2008

Overlays can do more ... if not everything

Jörg Liebeherr, University of Toronto


Application-layer peer-to-peer overlay networks have shown to be a disruptive technology. The ability to create large networks on-the-fly has enabled new application services in support of content distribution, file sharing, video streaming, and interactive teleconferences. But could the role of self-organizing overlay networks be even greater? Is it conceivable that peer network protocols become the foundation for a new architecture that is entirely based on the concepts of self-organizing overlays networks? Can peer network protocols evolve into a follow-on technology to the Internet protocols? We claim that potential and fundamental limits of the peer networking approach remain largely unexplored. We envision a network architecture characterized by the coexistence of virtually unlimited numbers of peer networks that can quickly grow to arbitrarily large sizes and adapt to changes in the number of peers and substrate networks. Using applications that we built in recent years, including a situation awareness system for emergency responders, a video streaming in mobile ad-hoc networks and others, we make the case that the overlay networking approach is vastly superior in situations with unknown, uncertain, and changing requirements for information access. We report on our efforts on putting overlay networking closer to the hardware, and discuss the challenges of running overlay protocols directly on mobile devices, access points, and packet switches.


Jörg Liebeherr received the Ph.D. degree in Computer Science from the Georgia Institute of Technology in 1991. He is currently with the Department of Electrical and Computer Engineering of the University of Toronto as the Nortel Chair of Network Architecture and Services. He is a co-author of the textbook ``Mastering Networks: An Internet Lab Manual, published by Addison-Wesley in 2004. He was elected to the Board of Governors of the IEEE Communications Society for 2003-2005, and chair of the IEEE Communications Society Technical Committee on Computer Communications in 2004-2005. He received an NSF Career award in 1996, a Virginia Engineering Foundation fellowship in 2002, a best paper award (as co-author) at ACM Sigmetrics 2005, and an Outstanding Service award from the IEEE Communications Society Technical Committee on Computer Communications in 2006. He is a Fellow of the IEEE. His current research interests are networks with service guarantees and self-organizing peer networks.