Study On QoS Problems Based On Overlay Network

Overlay Network is a virtual network which based on existing networks. It is composed of some logical links between service nodes and nodes distributing on the autonomy domains of the Internet .Overlay Network with the upper characteristic of flexibility and fault-tolerance is based on the underlying IP layer, so no large-scale modifies of underlying networks is required. With the rapidly development of the Internet, lots of applications with special QoS(bandwidth, delay, delay jitter, etc.) needs have emerged, such as VOIP and IPTV. However, the inherent disabilities of the existing Internet make it can not satisfy these applications'request of QoS. The overlay network emerges as required.Compared with the exiting network,the overlay network will have a huge advantage. Using the overlay network,we will be able to provide more reliable and fault-tolerance and better network services with no large-scale change to the existing architecture of the Internet .At the same time,some new applications can be deployed on the generic overlay network and specific overlay network which is designed for the specific application. Using the overlay network,even if the network layer routing errors occur, it can find a new routintg path. And it can And can be find the corresponding optimal routing path according to different QoS. Moreover, the overlay network is a virtual network over the existing network, so it don't need to change the current widely deployed network architecture, but also easier to implement relatively.In the research of overlay network, QoS routing is most important point, and it is also the focal point of this paper. Firstly kindly of QoS routing and corrective arithmetic are introduced and comprised with each other in this paper. Secondly, QoS arithmetic is discussed and analyzed. Based on OSN overlay network infrastructure, a new routing topology solution is proposed, and a new multiple QoS scale routing arithmetic MSRON is proposed further. GOSN topology scheme is simple but high efficient. It avoids network status imprecision when too many lays aggregate. In small and middle range overlay network, this scheme not only overcome node status information becoming tremendous and the number of nodes is limited thereby in original network topology, but also has the expandability advantage of layered structure. MSRON arithmetic which adapt Dijkstra routing method,considering the important network transmit factor bandwidth, latency and jittery, provide a best rout for overlay service request. MSRON,considering multiple QoS factors has the abilities to provide satisfying service for overlay network requests, specifically for the audio and video data transmission which are sensitive to delay and delay jitter. At the same time, MSRON arithmetic also can balance network resources, including the nodes'capability and links'bandwidth. The simulation results prove that the MSRON arithmetic can provide more efficient QoS satisfaction comprised to other similar routing arithmetic and better abilities to balance the valuable network resources.