Reserches On The Router-Based QoS And Its Simulation Analyzing Using Network Simulator

Quality of Service (QoS) is an important technology to provide better service to peer-to-peer systems. Nowadays an increasing number of different applications are continually conveyed by IP networks. These applications are causing more performance and service requirements. QoS mechanisms on the terminal systems can not provide satisfied QoS assurance any more. Routers begin to play the critical role in the peer-to-peer QoS structure. Being the middle node of IP network, Routers can easily sense the status of networks. QoS on the Routers can archive more complex functions than QoS on the terminal systems. Recently,a lot of researches are focused on the QoS mechanisms such as queue technologies and packets drop algorisms.This thesis is work aims to the QoS functions on the Routers. In this thesis, first, raise a conceptual Router QoS model, and then improved the simulation capabilities of the Network Simulator (NS), including the realization of four fair queue algorisms: Weighted Fair Queue (WFQ), Worst-case Fair Weighted Fair Queue plus (WF2Q+), Self-clock Fair Queue (SCFQ) and Start-time Fair Queue (SFQ). In addition, two measurement abilities are added: One-Way Delay (OWD) and IP packets Delay Variation (IPDV).At last, did some simulations and analysis on the Router QoS.