Research And Simulation Of Bandwidth Broker-Based QoS In Network

The evolution from traditional network to NGN is the inevitable course .Trough the convergence with IP-based core network ,NGN provides multi-services include multimedia service to users, which require strict QoS .While IP networks which provide best effort service can't ensure QoS, so can't meet the NGN bearer network's requirement. To ensure the end-to-end QoS is an urgent affair for NGN.This thesis deeply researches the architecture of QoS, including IntServ, DiffServ, and MPLS network put forward by IETF and other orgnizations. Aims at the problem that current IP network's routers don't have any policy to manage the bandwidth resource thus leads to poor QoS , this thesis starts with the management of router's bandwidth and provids an end-to-end network QoS architecture based on Bandwidth Broker .It divids the NGN bearer network into two layers based on the idea of layered network . One is data transport layer constituted with routers and another is source manage layer, BB , which manage bandwidth resources of routers in domain . This thesis describs the design of the BB and realizes all the function modules of BB on OPNET. In addition, some changes are done to the edge routers so they can be managed by BB . Material study is made in the aspect of call signaling and the configure protocol used in the communication of BB and edge routers. This thesis gives a realization of QoS signaling advocated by IETF, and also explores to choose the COPS-PR as the configuration protocol between BB and router.This thesis gives whole realization of IP QoS architecture based on BB in OPNET, and makes a contrast experiment with the pure DiffServ network. The results indicate that DiffServ network without the function of admission control can't avoid congestion when the high prior flows flood, and will worsen the performance of the network rapidly. While by the use of BB, bandwidth is managed and admission control is introduced, the system can avoid congestion...