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内容記述 |
Since current networking technology is rapidly evolving, many users can now access information from all over the world without any geographical and temporal constraints.<br />Networks are now a fundamental infrastructure for social services, such as E-commerce, online banking, social networking services (SNS), and cloud computing. As a result, cur-rent networks must provide a flexible service composition and robust system components.<br /> Most networks are currently based on TCP/IP protocol suite, and any application that supports it can communicate with another application without custom-made protocols.<br />Networks have evolved by incorporating extended functions on the TCP/IP core functions that are complementary without actually changing them. Current networks basically have both old-fashioned systems, and cutting-edge systems.<br /> There is a hierarchical structure referred to as an hourglass based on TCP/IP in the background of the universality of the fundamental networking capability. The main idea of this structure is that the TCP/IP ensures there is a logical connectivity between end-to-end applications. Users can introduce a variety of applied networking services on TCP/IP and physical access technologies under TCP/IP. However, since there still are many systems that only support traditional networking services, it is difficult to widely deploy advanced services in the network, and users may struggle to replace core network protocols with new protocols to correct a backward compatibility problem.<br /> Generally, it is believed that networking applications and services are evolving as the network environment expands and diversifies. However, a variety of dedicated systems that depend on particular platforms and the developing environment have appeared that lack a higher-level common platform for these advanced networking services and users have developed their own services, respectively.<br /> In this paper, we would like to discuss a common software platform for diversifying networking services. Not the only network software, such as the applications, ervers, and protocol stacks, but also the methodologies and implementation techniques are expected to provide a common software platform. In particular, instead of developing brand-new network systems, existing software assets and technologies are used to construct the advanced network environment.<br /> To achieve extensible network softwares, we have focused on a notion of an adap-tive communication. The dap-tive communication provides a way to adaptively compose networking capabilities of applications when the surrounding environment is changed.<br />In practice, each networking function for the application could be added, removed, or replaced per functional unit, and therefore, a transparent mechanism that dynamically composes networking functions is required to ensure compatibility with existing systems.<br /> Network applications usually use socket interfaces that abstract the networking functions to communicate over the network. A socket interface generally supports two types of communication: connection-oriented communications and connectionless-oriented communications, and it allows for the construction of network software that is independent of the network protocol. So, I am proposing a system that enables networking functions to be transparently change an application by using the abstraction of the socket interface. Since the change in networking functions is conducted entirely within the socket interface,the application can use the socket interface as is.<br /> Many related systems that transparently change the networking functions of applications. However, there are some platform, performance,developer-oriented behavior,usability, and flexible functions composition restrictions that exist with these systems. This study aims at a more pragmatic system compared to these systems in that it has a component-oriented function, composition mechanism, minimum overhead, multi-platform support, and a unified usability by taking into account not only the methodology for transparent extension, but also a common-platform for higher-level services characteristic. In addition, we take into account a user-interface that targets non-professional users as well as developers in the paper.<br /> In this paper, the proposed system was designed and implemented to work on Windows and Linux operating systems, and evaluated its functionalities comparing with existing systems. The result showed following advantages;<br /><br /> ● Users can extend and configure their systems as intended<br /><br /> ● Non-experimental users also can utilize the proposed system without programming<br /><br /> ● The proposed system can be available with more applications and operating<br /> systems<br /><br /> ● Users can manage the proposed system without difficulty<br /><br /> Therefore, the proposed system allows us to extend applications more concisely and finely on variety of network environments, and existing software asset can be leveraged to compose advanced network environment.<br /> In addition, performance overhead of the proposed system was measured by comparing with another application that equips network functions directly.The result showed that overhead of transmitting/receiving each user data was slightly several thousand clocks, and this value can be negligible considering that fluctuation time of the packet processing within the kernel protocol stack and packet transferring on the actual network. As a result, the proposed system could not be performance bottleneck on practical network systems. |
要旨・審査要旨 (329.6 kB)
