MAINTENANCE TEST SYSTEM BETWEEN LAN CONNECTION DEVICES AND LAN CONNECTION DEVICE

摘要

A LAN connecting device connectable to a LAN and connected to its opposite party device through lines 202 and 203 each using an optical fiber as a physical medium is provided with a communication data control portion 208 for performing an ordinary LAN communication between terminals of a physical communication or between terminals of a logical communication, a maintenance data control portion 218 for performing a test of communication, and an optical multiplexer 211 and an optical demultiplexer 213 for multiplexing and demultiplexing the input/output wavelengths of the communication data control portion 208 and the maintenance data control portion 218, and optionally performs a test of communication by means of the maintenance data control portion 218, and therefore, even such a LAN connecting device as a bridge, switch, repeater or the like not having a protocol up to the OSI layer 3 makes it possible to perform a test of a path between communication terminals, between repeating devices or between a communication terminal and a repeating device, and perform an operation test on these communication terminals and repeating devices. <IMAGE>