Shingo Ata

IPv6 anycast for simple and effective service-oriented communications

Although anycast communication supports service-oriented addresses, many of its current definitions in IPv6 are unclear. Furthermore, since there are no protocol standards or even a consensus on controlling routing, intersegment anycast communications are not yet available. In this article we first review IPv6-based anycast communication. At present, there are several possible applications that are suited to this. We then raise several problems and provide possible solutions to these. Based on this background, we present the Anycast Address Resolving Protocol (AARP) to establish TCP connections with a specific anycast address, and then propose a routing protocol for intersegment anycasts. Our proposed architecture makes anycast addresses.more useful without (or with at most minimal) need for modifications/extensions to existing applications and/or upper-layer protocols.

Protocol design for anycast communication in IPv6 network

Although anycast communication supports service-oriented addresses many of its current definitions in IPv6 are unclear. Furthermore, since there are no protocol standards or even consensus on routing control, inter-segment anycast communications are not yet available. In this paper, we first discuss these problems and solutions. Based on our findings, we present the anycast address resolving protocol (AARP) to establish TCP connections with a specific anycast address and propose a routing protocol for inter-segment anycasts. Our proposed architecture makes anycast addresses more useful without (or at most minimum) modifications/extensions to existing applications and/or upper-layer protocols.

On performance prediction of address lookup algorithms of IP routers through simulation and analysis techniques

Many address lookup methods on IP routers have been recently proposed to improve the packet forwarding capability; nevertheless, their performance prediction is very limited because of lack of consideration of actual traffic characteristics in their evaluations. It is necessary to consider actual traffic to predict more realistic performance in routers, especially in the case of layer 3 and 4 switches whose performance is more influenced by flow characteristics. In this paper, we propose new methods for predicting the routers performance based on the statistical analysis of the Internet traffic. We also present an example of its application to the existing table lookup algorithm, and show that simulation results based on our method can provide accurate performance prediction.

Performance comparisons of ABT/IT and DT in ATM networks

ATM block transfer (ABT) is promising for effectively transferring highly bursty data traffic in ATM networks. We develop an approximate analysis for two types of ABT (ABT/DT and ABT/IT) to discuss performance comparisons of ABT/IT and DT. Through numerical examples, we show that ABT/DT is quite sensitive to propagation delays while ABT/IT is not. We next investigate the performance improvement by dynamic bandwidth negotiation, which is applicable to ABT/DT. Bandwidth reduction methods in both of ABT/DT and IT are also examined. Simulation results show that the bandwidth negotiation can improve the performance of ABT/DT, and that in the case of short propagation delays, it outperforms even ABT/IT in terms of throughput. However, it is obtained at the expense of the increased burst transmission times. On the other hand, the bandwidth reduction allows a flexible use of the bandwidth, leading to fairly good performance in all parameter regions.

Performance improvement of ABT protocols with combined bandwidth/buffer reservation

ABT (ATM block transfer) is expected for effectively transferring highly bursty data traffic in ATM networks. In the past work, ABT/IT has been shown to be robust in that its performance is not much affected by the propagation delay when compared with ABT/DT. However, when the traffic load becomes heavy and/or when the number of hop counts of the connection becomes large, the throughput of ABT/IT is drastically decreased. We propose a new protocol, buffered ABT/IT, which makes reservation on the buffer as well as the bandwidth. The approximate analysis method is then developed for buffered ABT/IT. Through numerical examples, we show that it can much improve the performance even in the above conditions by comparison with the exiting ABT protocols.

Analysis and application of network traffic characteristics to design high-speed routers

A rapid growth of the Internet and proliferation of new multimedia applications lead to demands of high speed and broadband network technologies. Routers are also necessary to follow up the growth of link bandwidths. From this reason, there have been many researches on high speed routers having switching capabilities. To have an expected effect, however, a control parameters set based on traffic characteristics are necessary. In this paper, we analyze the network traffic using the network traffic monitor and investigate the Internet traffic characteristics through a statistical analysis. We next show the application of our analytical results to parameter settings of high speed switching routers. Simulation results show that our approach makes highly utilized VC space and high performance in packet processing delay. We also show the effect of flow aggregation on MPLS. From our results, the flow aggregation has a great impact on the performance of MPLS.