Research And Simulation For QoS Based Carrier Network In The UniOne

The thesis comes from the project of NGN QoS for the China Unicom.At present, the best effort service model of Internet is hard to satisfy the development of new real-time services for ISPs, clients' requirement for QoS and the problem of proper allocation for network resource. Along with constantly improvement maturation of NGN technology which is based on soft-switch, the advantages of NGN in network merging services conjunction and QoS will be reflected gradually. Taking it as a long term strategy, the China Unicom Sichuan branch believes that set up the NGN (UniOne) can improve the efficiency of network resource, the QoS of network, and above all, it will bring China Unicom to a new opportunity.The thesis researches some main QoS models and key technologies of UniOne, takes MPLS into account. The thesis also analyzes the technologies in UniOne through simulation, gives some suggestions to improve network's QoS. Researches in the thesis are focused on aspects shown below:1.First, the influence on traffics' QoS of different queue management and queue scheduling mechanisms are examined. Simulation results show that WFQ and WRED improve the QoS of UniOne.2.Two important IP QoS architectures (IntServ, DiffServ) are researched in this paper. The good simulation results show that DiffServ can provide some QoS to the multimedia services in UniOne.3.Analyze and compare some routing protocols, such as RIP, OSPF and BGP; Simulation results show that OSPF and BGP improve the performance of network.4.This paper also introduces the MPLS which is how to support IP QoS technology and the MPLS/VPN of UniOne. Simulation results show that MPLS/VPN can improve the UniOne' QoS greatly through combining MPLS with DiffServ.