Overlay Networks

Overlay networks are user-definable networks created over the underlying Internet (IP) networks which typically serve end- users with the best-effort service model. In overlay networks, overlay nodes which serve as the service access point and data forwarding facility utilize redundant paths and bandwidths of the Internet to transfer their service data. Since the overlay nodes are owned by the application-service providers (ASP) instead of the Internet Service Provider (ISP), all aspects of the overlay network including topology and application-specific QoS (Quality of Service) can be customized. Several research topics are still open in designing such an overlay network. These include overlay network creation strategy, overlay network topology adaptation, multipath flow routing protocol, application-oriented overlay routing protocol, overlay network service provisioning protocol, etc.

Dynamic Topology Wireless Network

Recently, wireless network services are widely available due to the availability of smaller, smarter and cheaper portable devices, inexpensive wireless technology, and mobile user’s demand for “anyone anywhere anytime” information access. There has been much interest in dynamic wireless networks which can evolve/adapt themselves according to the changes of the volume and geographical distribution of services’ demands generated by the end users. One possible solution is to let network equipment such as the wireless service access points or mobile routers change their positions appropriately to such demand changes in order to maintain the service quality and best utilize networking resources. The research topics include user tracking algorithms, users’ demand anticipation algorithms, topology adaptation algorithms, very fast dynamic routing algorithms, etc.

Active Network

Currently, networks become more and more dynamic in terms of both their size and their provided services. The existing execution paradigm of the routers may not react well to such networks’ dynamism. Active networking is the framework which allows sending code (executed at any intermediate network node) with the users’ information inside the data packets. This allows the possibility of highly tailored and rapid “real-time” changes to the underlying network operation according to the dynamism of the networks. For an example, the data packets can decide to change their way themselves when facing link failure or finding better paths. The overlay node is one of the potential applications of the active networking. Active network research addresses the nature of how best to incorporate extremely dynamic capability within networks. The research topics include active code structure, active node execution architecture, active code security, etc.