QoS Scheduling for the Multimedia Internet-Dynamic and Mixed
| Autor: | Yong-Hua Huang, 黃雍華 |
|---|---|
| Rok vydání: | 2004 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 92 Because of the diversity of information (such as voice, FTP, E-mail), and the largr amount of traffic, the traditional best-effort service model can no longer satisfy the user’s different requirements for the quality of service (QoS). In order to satisfying different QoS requirements, IETF has developed two different network architectures, namely integrated services (IntServ) and differentiated services (DiffServ). The IntServ allocates resource for every traffic flow individually and the core routers in IntServ architecture perform all the tasks. Although the resource can be distributed accurately, the scalability in IntServ architecture is poor. The DiffServ classifies QoS into five classes and traffic flows belong to the same class could accept the same forwarding treatment. Altough the granularity offered is not as good as IntServ, the problem of scalability and complexity in IntServ can be slved. Packet scheduling algorithms can be used to provide the various QoS requirements successfully no matter in IntServ architecture or DiffServ architecture. A static scheduler is easily implemented but poor in tackling burstiness, and a dynamic scheduler is adaptive to network status but complex in computation. This thesis would study two scheduling schemes. First, the Jumping Virtual Clock (JVC) is investigated. The JVC used the concept of dynamic scheduling and Leap Forward Virtual Clock for the objects of low computation and delay performance. Secondly, the Jumping Virtual Clock Round Robin (JVCRR) is combines the advantage of JVC and Round Robin. The network capability could be allotted with good flexibility and with good fairness. In this thesis, the performances of JVC and JVCRR are compered with some famous scheduling algorithms by simulation. It can been seen our proposed scheduling algorithms possess excellent performance to meet the different Qos requirements. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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