Distributed Call Control System and Cost/Benefit Trade-off Problem

摘要

A new distributed call control system based on ITU-T H.323 recommendation for multimedia telecommunication services in an IP-based network is proposed in this paper. This distributed call control system is referred to as the DCCS. The DCCS is compatible with current IP-based networks and technologies and is aimed at the Enterprise network. Therefore, the DCCS must effectively manage cost and Quality of Service (QoS). The DCCS references ITU-T H.323 and other related recommendations. For compatibility with current IP technologies, the DCCS should be based on the Ethernet, ISDN, PSTN, ATM, Frame Relay and FDDI technologies. The DCCS is composed of zone controllers (ZCs) which correspond to gatekeepers in H.323. A ZC has a purpose of providing enterprise users a benefit with respect to cost and application satisfiability. The benefit is QoS which is measured by bandwidth, delay and error ratio. However, bandwidth is limited and it can be costly to get more network resource for better QoS. The problem is balancing better QoS with the fewer cost, and is called "Cost/Benefit Trade-off problem". A solution to the problem is the Fairly Benefit Method and is the one proposed and discussed in this paper.