| 摘要 |
<p>PURPOSE:To provide a path trace system in which trace can be quickly operated even when the number of devices is large, and a faulty part can be easily specified when a trace abnormality occurs. CONSTITUTION:An OAM cell 8 for trace control which is transmitted at a speed as high as a user cell is allowed to flow to a virtual path to be tested, and control information for information collection at each intermediate point device 4, 5, 6, and 7 is set before an DAM cell 9 for information collection which is transmitted at a low speed reaches each intermediate point device. Thus, the information collection by the OAM cell for information collection can be efficiently attained. The OAM cell for information collection can be generated especially between the constant devices 2 and 6, and each OAM cell 9 and 12 for information collection can be allowed to independently operate information collection.</p> |
