Keio University, Graduate School of Media and Governance
MAUI Project
Ph.D. Dissertation

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TITLE A Research into Analysis of Operational Status on Large Scale and Global Infrastructure
ABSTRACT (Abstract) In this dissertation, a method to analyze the operation of a large scale and global infrastructure is proposed and evaluated. The DNS is taken as an example of such infrastructure, and the model together with its method in analyzing the operation of DNS is defined.

Furthermore, using the method, its application to analyze the operation status of DNS is confirmed. As a result, this dissertation achieved to propose a generic model to analyze the operation of a large scale and global infrastructure.

Large scale and global infrastructures, as represented by the Internet, have been increasing nowadays. Examples of such infrastructures are Global Positioning System(GPS), Global System for Mobile Communication(GSM), World Wide Web, and Domain Name System(DNS).

Such information-communication infrastructures are usually distributed autonomous systems, and they instantly became one of the necessities in our society. Therefore, strict requirements and demands on reliability and stability need to be fulfilled by each infrastructures. However, it is difficult to know the overall status due to the fact that they are operated autonomously. As a result, current troubleshooting takes reactive approach from the type of system failure. This approach is effective in the operation environment where change in the system operation occurs rarely. On the other hand, large-scale, global infrastructure mentioned earlier takes frequent change in scale and status, resulting in requiring longer period of time to discover the cause of failure.

In this research, DNS is used as one of the examples of large-scale, global infrastructure. Definition of model and establishment of techniques for analyzing operation platform of DNS is introduced. In addition, effectiveness of the techniques introduced in analyzing operation status of DNS is validated. Effective analysis model for analyzing large-scale, global infrastructure's operation platform is established as a result of the research.

The dissertation first describes the definition of a large scale and global infrastructure, and clarifies the requirements towards those infrastructures. The requirements are defines as; (1) fair and public service, (2) service reliability, and (3) identification of the service point.

The dissertation second describes the model to analyze the operation of a large scale and global infrastructure. The model is constructed from the following elements; (1) analysis of the service from user's point of view, (2) analysis of the service integrity, and (3) analysis of the information in service operation.

Analysis model for DNS operation platform is established based on the general analysis model for large-scale, global infrastructure introduced. The technique consists of following methods: (1) examination of DNS reachability (2) examination of DNS delegation tree (3) examination of identity of DNS servers For (1), time required for receiving reply is measured from different places in the world and the rate of receiving reply is also examined. In (2), integrity of DNS delegation tree is examined for DNS accuracy. In (3), service range for each DNS server is indicated by examining identification and operation information of DNS.

It is required to be aware of overall infrastructure regularly, in order to predict upcoming system failure. This research proposes analysis techniques for quantitative and constant examination of large-scale, global infrastructure and evaluation is taken by analyzing the systems in operation using the introduced technique. It is proved to be effective in analyzing the operation platform of large-scale, global infrastructure defined in the dissertation. As a result, the contribution can be made to proactively avoid system failure and provide system reliability and security using the proposed analysis model.

The dissertation as a result achieved to provide a method to efficiently analyze the operation of a large scale and global infrastructure.

CONTACT Thesis is available from this link (PDF, 5.5Mbytes, Japanese)
Please contact to the following email address when you download the file;
SEKIYA, Yuji (sekiya [at]

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