End-tn-End Measurement-Based Admission control

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When the traffic congestion occurs in VoIP network, voice quality may be degraded due to packet loss, delay and jitter. Admission control is required to limit the number of on-going VoIP sessions to maintain voice transmission quality. To this aim, a signaling protocol such as RSVP (Resource reservation Protocol) can be used. High level quality of voice quality is guaranteed with this method, since the forwarding devices such as the router make resource reservation before performing voice communication. However, this method suffers from scalability problems, because routers need to maintain per flow information for resource reservation. Moreover, all routers in the network should support RSVP. There is another method called end point admission control. In this method, only source and destination nodes are in charge of admission control and intermediate routers has no special functions for admission control, leading to higher scalability. This research focuses on end-to-end measurement-based admission control and quality of services management methods. The proposed method employs a way to make a decision of whether a call can be admitted or not depending on the network congestion state that is measured using probing probe packets between end points. This research has achieved several goals as listed below.1.Mechanisms for end-to-end measurement-based admission control.2.Admission control with alternate path environment.3.Network design for networks with end-to-end measurement-based admission control.4.Trial implementation of phone5.VoIP quality management systemBottleneck bandwidth measurement for an end-to-end network path