L0057C: BS_USR_NUM_BY_NULLNRI
This measurement provides the number of Users that are assigned to the proper MSC according to the NULL NRI load sharing in the TMSI with the MSC pool enabled. This counter indicates the number of Users that are selected to use the proper method to obtain the DPC according to the NULL NRI load sharing in the TMSI with the MSC pool enabled.
Integer number or integer.
With the MSC pool enabled, every time the BSC receives the acknowledgement message of establishing the A interface connection from the MSC (see measurement point A in Figure 1), the counter is incremented by one if the DPC is obtained from the mapping MSC in the NULL NRI field (the DPC algorithm is selected according to the NULL NRI field in the TMSI).
This is an original counter without involving any formula.