Networking of multi-domain unified communications systems: Structure design and performance evaluation

摘要

UC (Unified Communications) can integrate different terminals and media and has played animportant role in some enterprises. However, for large UC system with multiple domains, therestill exist unsolved issues such as large call delay, overlay management overhead, and bandwidthcostliness. In this paper, the hierarchal structure, call routing, and bandwidth usage of themulti-domain UC system are studied. After describing the architecture of the multi-domain UCsystem, a no-worse-than-two-hop query algorithm based on P2P is proposed for inter domaincall, and it is showed that 80% users can finish call query in one hop based on the derived performanceformulas. Then, the typical transmission networking structure is designed with an overlaybetween provincial domains, and the bandwidth requirements of signaling and media traffics areestimated. By comparing the performances of overlayswith mesh, star, and hybrid topologies, thehybrid overlay topology is showed to be the best choice in terms of cost and manageability for thetypical traffic distribution. In the overlay with hybrid topology, the media traffic routes can be controlleddynamically with SDN (Software Defined Network), and the overlay bandwidth reservedcan be used efficiently with utilization up to 84%, thus demonstrating the technical and economicfeasibilities of the proposed transmission overlay.