A Dynamic Scalable Video Conference System Based on SIP

摘要

The Session Initiation Protocol (SIP) provides powerful and flexible signaling capabilities for building video conferencing services. Traditionally, for SIP-based centralized video conference systems, the conferencing scale is mainly limited by both the capability of conference server and the availability of bandwidth. In this paper, our design focuses on how to provide dynamic scalability for the SIP-based video conferencing system when the number of conference users increases continually. Based on the study of the SIP protocol and the existing video conferencing models, we propose a dynamic scalable service model that can support to dynamically increase the number of conference servers without negative influence on the stability of system. This enables the extra service requests to be transferred and served in the cooperated conference servers. The paper also addresses the SIP-enabled conferencing flows based on the model in detail. We developed a prototype of video conference system based on the proposed model. Experimental results demonstrate the validity of this service model.