Journal for Academic Computing and Networking
Online ISSN : 2433-7595
Print ISSN : 1343-2915
Volume 7 , Issue 1
Showing 1-5 articles out of 5 articles from the selected issue
Original paper
  • Yasuo Musashi, Ryuichi Matsuba, Kenichi Sugitani
    Type: research-article
    2003 Volume 7 Issue 1 Pages 5-11
    Published: September 26, 2003
    Released: August 08, 2019
    JOURNALS FREE ACCESS

    The system log (syslog) files of the E-mail and the DNS cache servers in Kumamoto University were statistically investigated when receiving a lot of spam mails. The DNS query traffic between the E-mail and the DNS cache servers increases when many traces of spam and/or junk mails are found in syslog file of the E-mail server. The DNS query traffic decreases when preventing access between the E-mail server and the spam/junk transferring SMTP clients. This is because the DNS query between the DNS and E-mail servers are mainly driven by the SMTP access in the E-mail server. Therefore, we can detect abnormality of the E-mail server by monitoring the DNS query traffic from the E-mail server to the DNS server and get access-controlling list by analysis of the SMTP syslog files.

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  • Kazunori YAMAMORI, Kazuyuki HIRATA
    Type: research-article
    2003 Volume 7 Issue 1 Pages 13-22
    Published: September 26, 2003
    Released: August 08, 2019
    JOURNALS FREE ACCESS

    The DNS servers which exist scatteringly in a university are managed by administrators of each section. Recently the patch works for the DNS servers are needed frequently because the security holes are found many times. Those works are bothering the administrators. It is considered that the concentrated management from those many DNS servers to one makes the total loads of administrators reduced and makes the network security enhanced. In that case, in order to reduce the administrator's load of the concentrated system, it is desired that administrators of each section perform the DNS registration of the individual section. Thus, We have developed the system that each administrator can perform the DNS registration to the concentrated DNS server using each Web brauzer respectively. And all machines, which are assigned to IP address without DNS registration, can be registered simultaneously. Users can request the assignment of IP address from each Web brauzer. Moreover, because all machine's information are registered in the database, the network administration section like an information processing center can manage the total information of all machines in the university. It leads to enhance the network security. This paper introduces the developed system and shows the evaluation.

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  • Yoshitsugu MATSUBARA, Hirofumi ETO, Shin-ichi TADAKI
    Type: research-article
    2003 Volume 7 Issue 1 Pages 23-31
    Published: September 26, 2003
    Released: August 08, 2019
    JOURNALS FREE ACCESS

    It is necessary to construct a system indicating the terminal use status on demand, for servicing educational terminal systems. Lecturers using terminal rooms are able to know the student attendance for their lectures from the system. The system provides students the information on the number of terminal available for their homework. The information given by the system are useful for system administrators for maintenance. The information also are useful for planning future systems. We develop such a system, which provides the information through Web browsers and mobile-phone browsers.

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  • Tsuyoshi Kiyan, Yasushi Ohta, Hiroshi Nakano, Toshihiro Kita, Ryuichi ...
    Type: research-article
    2003 Volume 7 Issue 1 Pages 33-42
    Published: September 26, 2003
    Released: August 08, 2019
    JOURNALS FREE ACCESS

    As a part of the LINK (Local Initiative Network Kumamoto (Knowledge)) project, the network connection system was constructed between the Kumamoto Prefecture and the Kumamoto University with several network servers; Web, e-Learning, TV conference and streaming distribution servers. We have designed the the regional cooperation activities support system by the combination of the TV conference server and the streaming distribution server. The system can distribute the contents of TV conference as the live stream over the Internet by combining one of the TV conference client and the encoder client of the streaming server. We will present the system configuration for "The Regional contribution symposium in Kumamoto University" as an example, and discuss the problem of the degradation of the video quality and the audio delay, and indicate their solutions.

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  • Kouji Nishimura, Tohru Kondo, Koichi Tajima, Seigo Kishiba, Reiji Aiba ...
    Type: research-article
    2003 Volume 7 Issue 1 Pages 43-52
    Published: September 26, 2003
    Released: August 08, 2019
    JOURNALS FREE ACCESS

    The demand for video-based distance conference and distance learning is emerging for universities which have more than one campus or proceed to the interchange of its credits with other universities. However, as the Internet does not guarantee the QoS(Quality of Service), packet losses may occur even if there is enough bandwidth. The existing TV conference systems and tools have the problem with respect to the robustness against the packet losses. In this paper, we develop a high quality video transmission system with packet loss recovery functionality using FEC to deploy for the inter-university communications via the Internet. We describe not only the theoretical result but also the practical experiments on several networks.

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