Research On Self-adaptive Route Scheduling For VoIP Systems And Implementation

With the quick development of Information Technology and the Internet's arrival, applications based on exchanging the data in groups are prevailing gradually, as a newly-coming internet service, VoIP is being widely used now. But due to the bad internet condition and the best-effort mechanism, long-delay, big delay jitter and big packet loss rate accompany with VoIP sessions. The quality of VoIP session still can't satisfy the users' demand. In order to reduce delay in network and improve the quality of communication, the general solution employed in the VoIP systems at home is to create several redundant routes connecting between itself and PSTN(Public Switched Telephone Network), then judge the quality of routes and select a route schedule by manual work. However, the disadvantages of it are slow-response, low-reliability and high-cost realization. Therefore, the key approach to realize the high-quality VoIP phone is to do research on route scheduling policy and its realization algorithms and to realize self-adaptive best route matching.On the basis of analyzing the domestic network condition and existing situation of route scheduling arithmetics in VoIP systems, the paper studies the key realization technologies of route scheduling. For short-delay, small packet loss rate and small delay jitter in the high-quality VoIP phone, the solution is to embed load balance mechanisms into VoIP routing, periodically make use of probes to get the parameters of routes, such as route delay, packet loss rate and average response time, and then employ a self-adaptive route scheduling algorithm which is on the ground of Qos to intelligently select the best route between VoIP systems and PSTN. In order to evaluate route scheduling,the paper uses some measures that are to classify affairs, estimate link and analyze"chess". As a result, we can get a quantitive result of"chess". After that, for a quantitive analysis of the route scheduling algorithm in the terms of economy, we need to change the result into the"chess"power of link.In the end, the paper makes the VoIP system where route auto-scheduling is realized come true according to the above idea(The VoIP system is rooted in the project from the company of Shenzhen Uni-tech Communication). Besides, the design route and detailed design of key modules are presented. At the same time, an experiment has been done. In the experiment, I compare the new way with the traditional one by some criteria, such as, average packet loss rate and delay jitter rate.