The Research Of Priority Checking RED Algorithm Based On IPv6Network

In recent years, the number of users on Internet has grown exponentially, the scale ofInternet has grown increasingly, the development of network resource has not metincreasing demand of users, so network congestion is inevitable. Network congestioncauses a continuous decline in network performance, even causes network collapse.Therefore, an increasing number of researchers study network congestion issues as thedirection research, and put forward a variety of congestion control mechanism. The essenceof congestion control mechanism is to detect network congestion in order to take avoidancemeasures. However, according to the location of congestion control realization, congestioncontrol algorithms can be divided into two parts. On one hand, the control algorithms basedon source can adjust sending rate of terminal in the network, timely response to the changesin network load. On the other hand, the control algorithms based on link can perceivenetwork congestion, and take appropriate to avoidance measures.With the tireless efforts of the people, computer network performance is constantlybeing improved, but current network based on IPv4protocol exists a variety of defects, itwill restrict the continuing development of the network to a certain extent. Such as thenumber of Internet users surging, it will don’t have enough address capacity to meet theworld’s needs; with complex changes in network structure, it will result in rapid expansionof the routing table and greatly reducing routing efficiency; with the rapid changing ofnetwork requirements development, it will don’t have a better quality of service options.Therefore, the next generation of Internet applications based on IPv6protocol is caused forconcern. IPv6protocol inherits the advantages of the IPv4protocol and it modifiedinadequacies accordingly. The changes of address space is not expanded simply, it willrevise the original address hierarchy in order to improve the efficiency of routing. At thesame time, due to changes in the IPv6header, it will be possible to allow the diversifieddevelopment of the quality of service. In conclusion, IPv6network applications brought usmore choices and challenges.Although compared IPv6network and IPv4network, it exists unparalleled advantage,but it still exists network congestion problems, that become a key factor to restrict thedevelopment of next generation internet. Thus, network congestion control is still one ofthe major tasks for researchers. However, how to use the features of IPv6network, flowlabels, combining with the existing congestion control mechanisms is still in the discussionof the research stage. In this thesis, by studying classic RED algorithm, it concludes thatRED algorithm is able to absorb burst data stream, can avoid global synchronization. It is asimple control principle implemented easily. But the problem that it is sensitive to set parameters, TCP/UDP fairness issue and can not distinguish services can not be ignored. Itis unable to distinguish user grade to support levels of service, for this issue, by combiningIPv6flow label field with RED algorithm, this paper presents an active queue managementalgorithm that can distinguish user priority—priority checking for RED algorithm. At thesame time, improved algorithm not can distinguish user priority, but also discard the packetof different levels of user with different drop probability. And it can ensure datatransmission to meet QoS requirements for priority user.In this paper, it will simulation through network simulation software OMNeT++.There are not only experimental simulation between IPv4environment and IPv6environment to compared, but also simulation for improved algorithm in IPv6environment.It can be seen that improved RED algorithm can distinguish priority of user and ensurequality of service for priority from the experimental.