Research On Quality Of Service Guarantee Technology In IPv6

With the rapid development of the Internet, more and more real-time services were transferred. These services asked for higher requirements in bandwidth, delay, and jitter. While the current Internet based on IPv4 only provides the best-effort services, then this mechanism cannot satisfy these requirements. IPv4 network will be developed in the direction of IPv6. Meanwhile, the network business in IPv4 will be transferred to IPv6. It's a key problem for future IPv6 to provide reliable network service and QoS guarantee.The aim of IP QoS is to offer end-to-end QoS control or guarantee effectively. Because of the similarity between IPv6 and IPv4, QoS guarantee technologies in IPv4 have got a better development. We can use the QoS fruits of IPv4 for reference before the lager-scale deployment of IPv6, and application of Integrated Service model, Differentiated Service model, MPLS and so on QoS technologies to IPv6 network. The research during these years shows that the algorithm of network routing plays an important part in providing quality-of-service guarantees. The study of QoS routing has become a very important study direction in research field of QoS. Considering that network model based on multiple constraints can reflect QoS routing problem in practice more accurately, so this paper mainly studies QoS routing algorithms based on multiple constraints in IPv6.This paper firstly introduces the basic features of IPv6 and key technologies of IP QoS, and it summarizes the problem of every technology. Then it studies how to apply Traffic Class and Flow Label and Hop-by-Hop Extensions Header and routing Extensions Header in QoS guarantee, and proposes the method of realizing the Integrated Service model by using Hop-by-Hop Extensions Head. Moreover, according to the condition that more work has been done in schedule methods, congestion control and resource reservation, so this paper does more work in researching QoS routing. This paper has analyzed the relationship between QoS routing and QoS framework, and has studied the existed multi-constraint QoS routing algorithms. Based on the flooding algorithm in IPv4, it proposes a multi-constraint QoS routing algorithm based on selective flooding in IPv6. The basic idea of selective flooding in IPv4 is used to reduce the numbers of probe packets and avoid route loop. Flow Label is used to identify the traffic class and accelerate packet classification. Hop-by-Hop Extensions Header is used to record QoS request and complete admission control. Routing Extensions Header is used to trace the path of probe packets and provide the return path of confirmation packet. This algorithm not only reserves the advantage of flooding algorithm in IPv4 and overcomes its disadvantage, but also adapts itself to IPv6 network. Lastly, this paper tests the algorithm by using NS-2 and comes to the conclusion that the algorithm can reduce probe packet's number greatly, so it can lighten the network burden.