GCP A Group Communication Protocol for Supporting Closed Groups in the Internet

摘要

Video conferences have become a popular application in modern high performance networks. Advanced technologies allow their installation on desktop computers. Currently videoconferences are mainly deployed for large open group conferences in the Internet to transmit lectures, conferences, talks, and discussions. Multiparty video conference tools for closed group meetings are less broadly used. On the other hand, most meetings in every-day life are meetings of closed groups with a more or less confidential character. Unlike open group conferences closed group meetings require a sender related transmission paradigm, i.e. the sender must know the receivers of the data streams. This is usually solved by using a centralized group server for the group and the QoS management. The shortages of this approach are server failures and performance problems. The decentralized approach is more flexible, but it requires more sophisticated mechanisms to preserve the consistency of the management data at each participant. In the paper we present the signalization protocol GCP to support decentralized closed group video conferences. It provides an atomic, ordered, and reliable data delivery service and supports a dynamic join and leave of participants. We present two versions of the protocol: one for ATM networks using overlaid multicast connections and one for IP-based networks.