Research Of QoS Based On IPv6 Flow Label

The rapid development of the Internet has given birth to more and more the emergence of real-time services which require QoS have several characteristics of high-bandwidth, strict packet loss rate, a low delay and delay jitter. At present, the traditional "best effort" type of IPv4 cannot meet the needs of real-time traffic and this must be resolved. IPv6 excludes the burden. In addition to provide for QoS, IPv6 also set the flow label header field especially, which can be used to solve the QoS problem in network development.IPv6 is the next generation Internet vector that its original intention is to solve address depletion problem of IPv4, and QoS factors as well. so it is not the origin which overthrow the old network protocols, models and mechanisms, but the supplement and upgrade of IPv4 version. Therefore, in addition compatible with the old model mechanisms, IPv6 has been improved on the header format, to meet the needs of the network, so a natural service model of IP QoS is also apply for IPv6.This article introduces several popular models and their traffic conditioning mechanisms are described. This article found that In the real network, IntServ/RSVP is often combined with DiffServ and MPLS for the application to meet the needs of a variety of traffic. IntServ/RSVP is mainly supply resources based on quantity of traffic in the network. DiffServ simply mark the traffic and distinguish the priority and that have no specific mechanism to detect how much bandwidth needs; MPLS and DiffServ faces the same dilemma. Although RSVP can be done, its traditional regulatory mechanisms based on quantity of traffic cannot meet the real-time QoS needs. Above all this article proposes a way to readjust Bandwidth of real-time traffic.In order to improve IP QoS specially set 20 bits Flow Label field in IPv6, just as auxiliary to meet extraction of Bandwidth in this study, The International Organization about IPv6 have a clear definition for Flow Label, but there is no single, accepted mechanisms, some experts had developed some draft for its allocation and use, We introduced in Chapter three, in general, various form, the use of redundancy, duplication, waste valuable and limited Flow Label field. This article proposed a new Flow Label scheme.Based on the above analysis of factors, this article made the following work:(1) Based on the international situation of Flow Label field that is assigned and used, we proposed our Flow Label scheme based on Huffman coding and instructions were specifically addressed. We solved the problem of redundancy and overlapping functions, and simple, effective use of Flow Label field.(2)Combined with MPLS network and using Flow Label scheme of this article, based on the ideas of real-time traffic, we proposed a program of readjust Bandwidth to improve real-time QoS, and the concept of Virtual Label, calculated the total demand of Bandwidth, and comparison of initial Bandwidth, make a decision whether require formula arithmetic to adjust Bandwidth.(3)NS2 simulation software used to test, from the experimental results, such programs take full advantage of Bandwidth resource and improve the quality of service in real-time traffic.