Asynchronously Replicated Shared Workspaces for a Multi-Media Annotation Service over Internet

This paper describes a world wide collaboration system through multimedia Post-its (user generated annotations). DIANE is a service to create multimedia annotations to every application output on the computer, as well as to existing multimedia annotations. Users collaborate by registering multimedia documents and user generated annotation in shared workspaces. However, DIANE only allows effective participation in a shared workspace over a high performance network (ATM, fast Ethernet) since it deals with large multimedia object. When only slow or unreliable connections are available between a DIANE terminal and server, useful work becomes impossible. To overcome these restrictions we need to replicate DIANE servers so that users do not suffer degradation in the quality of service. We use the asynchronous replication service ODIN to replicate the shared workspaces to every interested site in a transparent way to users. ODIN provides a cost-effective object replication by building a dynamic virtual network over Internet. The topology of this virtual network optimizes the use of network resources while it satisfies the changing requirements of the users.