The Design And Implementation Of QoS-Filter Model System In Linux

As the rapid development of computer network, the traditional best-effort IP network is unable to meet the ever-increasing needs which imposed on network quality of service by real-time and multimedia traffic. The proposal of quality of service theory provides a transmission-level approach for those network applications which has particular requirement on the properties of QoS such as real-time multimedia application. Aiming at the various connect attributes and terminal systems with different processing capacity, the main research is about how to configure the network resources dynamically according to the diversified QoS requirment which has application value on the development of network. The paper gives weight on the design and implementation of QoS grading-filter modeling system which supports Video Layered Multicast System in heterogeneous network environment. Through analyzing the traffic control technology in Linux operating system, it actualizes the QoS-filter modeling Router system based on Redhat 9.0 by Linux's QoS assurance mechanism. The system is mainly composed by RSVP module and QoS-Filter module. RSVP daemon process communicates QoS_Filter program with the RSVP extended object (RSVP_QF) through the extended API interface. Qos_Filter program parses the service level and flow parameter in RSVP_QF object and realizes the dynamic filter of Layered data flow via traffic control interface. Chapter one introduces the basic theory and current research of QoS,and points out the necessity of research mentioned in the paper. Chapter two details the basic principle of Linux QoS assurance mechanism. Chapter three deals with the working mechanism of RSVP at first and then proves the validity and solidity by protocol realization and parameter simulation under the environment of OPNET. Chapter four expounds the details in actualizing the QoS-Filter System. First of all, it introduces the main function modules of the system. Afterwards it analyzes the QoS grading-filter modeling system from the aspect of data structure, implementing detail and flow. Chapter 5 proposes the testing scheme of QoS-Filter modeling system, and analyzes the test results. Chapter six makes the summary, points out the possible improvement and gains a perspective on the application of QoS-Filter modeling system.