Hitachi, Ltd.

Nippon Telegraph and Telephone Corporation

Nippon Polyurethane Industry Co., Ltd.

Toshihiko Fujita

Yoshihiro Ashi

Hiromi Ueda

Noriyoshi Yano

Haruhiko Matsunaga

A method and apparatus of tracing VP's (virtual paths) wherein operational information of VP connectors are collected through OAM (operation and maintenance) cells. The VP connectors establish a connection at a VP level within a network in which the cells are transferred in an ATM (asynchronous transfer mode). Each VP connector detects an OAM cell for VP tracing as received from another of the VP connectors, and judges if an area for affixing the operational information in the VP connector itself exists in the detected OAM cell. In the VP connector when the area exists, the detected OAM cell is specified to be the OAM cell for writing the operational information thereinto, and the specified OAM cell is sent out after affixing the operational information thereto. When the area does not exit, the OAM cell received from the other VP connector is sent out after indicating therein that the received OAM cell is not the rearmost cell, the OAM cell for the VP tracing is generated anew, and the generated cell is sent out after indicating therein that the generated OAM cell is the rearmost cell. Also the operational information is affixed to newly generated OAM cell.

Virtual path connector and virtual path tracing method and apparatus

A process for producing a polyoxymethylene-polyurethane type alloy, which comprises allowing a polyisocyanate compound, a short chain polyol with a molecular weight of 62 to 350, a long chain polyol with a number-average molecular weight of 400 to 5,000, and optionally additives to react with each other in the presence of at least one or polyoxymethylene polymers.

Process for producing polyoxymethylene-polyurethane type alloy

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Yokohama, Japan

Toshihiko Fujita