Research On Anycast Routing Protocol In IPv6

With the rapid development of the computer technologies and communication networks and especially the extensive application of the Internet services, anycast is one of three communication models defined by IPv6, and may play a more and more important role in many network applications. The prime problem of anycast is the design for highly effective anycast routing protocol, which is requested to determine the optimal path of multiple hosts in same address according to its definition. At the present time, the study of the anycast communication technique especially the anycast routing problem is still a new research field, and the study of the anycast communication technique is still at the primary stage so inevitably there exist some problems in performing it. These problems need further study and analysis.This paper has deeply analyzed and studied the existing problems of the anycast routing technique in various network environments and has proposed the effective solutions and the according routing protocol to solve them. The originalities and contributions of this paper are as follows:(1) This paper deeply analyzes and studies the problem of that most anycast multi-target routing protocols need global network information which leads to much routing node resource and link resource cost. An anycast multi-target routing protocol based on mobile agent is proposed. In the protocol, it needs only local network information and applies mobile agent to search anycast member, so it saves much routing node resource and link resource. In contrast to the multiple target anycast routing protocol based on OSPF environments which we proposed in the paper, simulations experiments show that network time delay performance of the protocol is improved due to the cost saving in routing nodes and link resource.(2) For bad performance of robustness of shortest path anycast routing algorithm in highly dynamic networks as an example of Mobile Ad Hoc Network, an anycast routing protocol based on density or distance is proposed. The anycast member selection of the protocol is determined by both the distance factor and anycast members surroundings (i.e. density). The value of parameter k adjusts the weight of distance and density hence influences respective selection priority of each anycast member. Routing towards a dense anycast member population increases the probability that a packet eventually reaches any anycast member because packets can more easily be re-routed to neighboring anycast members when the targeted one becomes unreachable, making this protocol's performance greater at robustness. The newly designed protocol is characteristic of adaptable. In the protocol, according to network status (link downtime and moving node speed), by adjusting parameter k, routing robustness and routing efficiency are better balanced.(3)For the energy-limited problem and wireless link quality problem in Wireless Sensor Networks, this paper proposed a Wireless Sensor Networks anycast routing protocol based on link quality. In the protocol, we discuss how to calculate the link quality (especially the probability of transmission collision). The routing criterion of the protocol is based on the hybrid of load balancing and minimum overall energy cost and we balance the two factors by parameter a. Experiment results show that performances are improved in terms of energy balancing and network energy consuming hence network lifetime is optimized.(4) This paper deeply analyzes and studies the influence to the anycast routing technique by client's QoS constraints. For bandwidth QoS constraint anycast routing problem, this paper proposed an anycast data flow routing protocol based on load balance. In the protocol, according to routing weight, admission control nodes select multiple paths to provide anycast data flow service; admission control nodes manage for resource reservation, retrial control and resource release. Experiment data shows that in high anycast data flow request frequency this protocol has great impact on the performance in terms of average service delay for the reason of load balance. For the problem of anycast routing protocol with bandwidth and time delay constraints, we proposed a polynomial time approximation optimization algorithm. Since this optimization question is a NP-hardness problem, our optimization algorithm is a near-optimal solution. Simulation results show that the performances obtained by our protocol are better than by our proposed heuristic algorithms (shortest path first anycast routing algorithm and maximum bandwidth path first anycast algorithm), especially in bandwidth-limited large-size networks.(5) This paper deeply analyzes and studies k-anycast routing technique and proposed a k-anycast routing protocol based on component and mobile agent. The protocol forms multiple components and each component has at least k members. Thus, the protocol is distributed and multipath because k-anycast routing problem can be distributed to each component. Moreover, mobile agents which fit for distributed management are applied to initiate or manage components and routing table. Simulation results show the performances of the proposed protocol are improved in terms of communication cost, time delay and scalability. For both the property of wireless broadcast advantage and the character of energy-limited in wireless sensor networks, this paper propose a wireless sensor networks k-anycast routing protocol based on broadcast scheme. In the protocol, by adjusting radio power, the sender can send a packet to multi-objective simultaneously. Moreover, the objectives of both energy balancing and network energy consuming are optimized in the protocol. Experiments results show that performances of this protocol are improved in terms of energy balancing and network energy consuming hence network lifetime is optimized.