Virtual path test function and its mechanism for ATM transport networks

This paper considers a function to improve the efficiency of the operation administration and maintenance (OAM) of the virtual path (VP) in the ATM network. A VP test method is proposed which can test the connectivity and performance at new VP establishment and locate the fault point at VP failure. The implementation of the method is discussed. The feature of proposed method is that the number of error bits, the number of lost cells, and the number of misdelivered cells can be measured by transmitting and receiving the test OAM cell in any test section of VP. In this paper, the purpose and requirements for the VP test system are described first. Then the mechanisms in the proposed system and the allocation of test functions are considered. A transmission performance measurement algorithm is proposed for the test OAM receiver so that the bit error, the cell loss, and the cell misdelivery can accurately be counted. The structure of the VP test OAM cell to realize the proposed algorithm is presented. Finally, the system parameters of the proposed method are evaluated quantitatively.