A Flexible Concast-Based Grouping Service

We present a scalable and flexible grouping service based on concast and best-effort single-source multicast. The service assigns participating end systems to specific groups based on application-supplied criteria. Example uses of such a service include peer-to-peer applications that want to group machines that are “near” each other, and reliable multicast services that need to assign receivers to repair groups. Our generic grouping framework relies on concast’s many-to-one transport service to efficiently collect and apply the applicationspecific grouping criteria to the group members’ information, and it relies on single-source multicast (i.e., one-to-many communication) to distribute the results to the nodes being grouped. The service can easily be customized to meet the grouping requirements of the application. We present simulation data showing the convergence properties of our grouping service and its effectiveness when applied to the problem of constructing overlay networks.