In early work, together with Robbert van Renesse and Dan Dumitriu, I built and evaluated the performance of  SelectCast, an application level multicast protocol.  SelectCast goes beyond previous work on Application Level Multicast Routing Protocols (ALMRPs) in the following two ways:

• SelectCast offers users great flexibility in how to select routers.  For example, routers can be selected to minimize latency or maximize throughput. The default selects routers based on longevity, thereby attempting to optimize robustness. The selection may be changed at run-time.
• SelectCast allows senders to specify the set of intended destination hosts through the use of a SQL condition on selected attributes of such hosts.  Note that this is different from publish/subscribe systems in which the subscribers specify what messages they are interested in receiving, either by topic or by a predicate on messages.  Our strategy is strictly more powerful than traditional topic and content-based publish/subscribe mechanisms.

I am currently developing FastCast, a routing Infrastructure for IP multicast–based WAN applications. FastCast allows members of WAN applications to send, and receive messages using the standard IP-multicast interface. Usually, the members of WAN applications reside in different Internet sites that exploit their choices of hardware multicast. Using the FastCast infrastructure, a WAN application multicasts messages to an IP multicast address. FastCast sends the application’s messages between sites using a tree of TCP connections built using control information received from an ALMRP component. Each dissemination tree has assigned a Flow ID. The ALMRP may be chosen based on the application’s choices, and the number of sites used by the application. When several applications use the same AMLRP between the same sites, FastCast reduces ALMRP overhead by disseminating messages through the same tree of TCP connections. Moreover, in order to be TCP-friendly, FastCast uses at most one TCP connection between any pair of sites, and may run a credit-based flow control on each TCP pipe. 

By using the FastCast infrastructure, site members receive original IP multicast packets regardless of where senders reside. Sites can use their choices of IP multicast protocols without changing their software. The FastCast infrastructure is able to change the ALMRP assigned to an application on-the-fly and experiences less “churn” by adding and dropping IP multicast addresses at the site level instead of the host level. The FastCast infrastructure separates the data path from the control path for any choice of ALMRP. Such separation improves forwarding performance and updates ALMRPs on-the-fly.

Publications

1. Adrian Bozdog, Robbert van Renesse. FastCast: A routing infrastructure for Ip-multicast based WAN applications. Work in progress.
2. Robbert van Renesse, Adrian Bozdog. Willow: DHT, Aggregation, and Publish/Subscribe in One Protocol. Proc. of the International Workshop on Peer-to-Peer Systems (IPTPS '04). February 2004, San Diego, CA.
3. Robbert van Renesse, Kenneth P. Birman, Adrian Bozdog, Dan Dumitriu, Manpreet Singh, Werner Vogels.  Heterogeneity-Aware Peer-to-peer Multicast.  Proceedings of the17th International Symposium on Distributed Computing (DISC 2003).  October 2003. Sorrento, Italy.
4. Adrian Bozdog, Robbert van Renesse, Dan Dumitriu. SelectCast -- A Scalable and Self-Repairing Multicast Overlay Routing Facility. Proceedings of the First ACM Workshop on Survivable and Self-Regenerative Systems. October 31, 2003. Fairfax, VA.
5. Adrian Bozdog, Robbert van Renesse, Dan Dumitriu. The Performance of SelectCast -- Scalable and Self-Repairing Multicast Overlay Routing. In submission .