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Satoshi KATSUNO Katsuyuki YAMAZAKI Takahiro KUBO Tohru ASAMI Kiminori SUGAUCHI Osamu TSUNEHIRO Hiromichi ENOMOTO Kenichi YOSHIDA Hiroshi ESAKI
As the number of Internet applications in critical situations increases, the quality assurance of the network infrastructure becomes more and more important. The operators of such networks have to maintain the network as reliable and available with sufficient performance. Measurement technology is the key to maintaining the network condition and provides the network as being the important infrastructure of the network society. To meet these requirements, a high-speed and accurate IP meter, HIM, has been developed. Specific hardware has been made to realize the necessary specifications that enable data capturing with 20-µsecond order timing information from a gigabit class network. The experimental results with HIM show that: 1) software-based equipment cannot handle 100-µsecond order timing information, 2) the current computer system can transmit a high-speed (30 Mpbs) multimedia stream in accurate timing (jitter less than 20 µseconds) with UDP, 3) but TCP's retransmission mechanism makes the jitter worse (up to 264 mil seconds) and, 4) WAN's one-way traffic exhibits some strange behavior, which requires further investigation.