Abstract: An information processing device includes a buffer that stores data blocks of a plurality of flows and from which the data blocks are sequentially read; a processor coupled to the buffer and configured to: monitor an input rate that is a sum of data amounts of the plurality of flows input to the buffer per unit of time, and suppress flowing of a data block into the buffer for one or more of the plurality of flows based on a result of monitoring the input rate.

Abstract: In a point-to-multipoint network of an optical line terminal (OLT) and multiple optical network units (ONUS) wherein each ONU is enabled to send a signal only within a time period enabled for the ONU, the OLT (or a system installed therein) identifies a defective one of the ONUs. For each of a given series of time periods, the OLT measures an optical reception level of an optical fiber signal in the time period. The OLT stores, in advance, in a table at least the reception level of a received signal from each ONU in association with the ONU. The reception level is measured in a normal state where signals from the ONUs are exclusively received. For each of the given series of time periods, the OLT decides whether a signal from one of the ONUs associated with the time period is exclusively received with no collision with any other signal.

Abstract: In an optical transmission method and device of a point-multipoint type, whether or not identification information of an optical network unit designated is received within a fixed phase tolerance for a transmission enabling phase designated to optical network units on multipoint sides is determined. When it is determined that no identification information of the optical network unit designated is received and identification information of any optical network unit is received up to a transmission enabling phase subsequently designated, a transmission stop command is transmitted to the optical network unit whose identification information is received.

Abstract: In an optical transmission method and device of a point-multipoint type, whether or not identification information of an optical network unit designated is received within a fixed phase tolerance for a transmission enabling phase designated to optical network units on multipoint sides is determined. When it is determined that no identification information of the optical network unit designated is received and identification information of any optical network unit is received up to a transmission enabling phase subsequently designated, a transmission stop command is transmitted to the optical network unit whose identification information is received.

Abstract: In a point-to-multipoint network of an optical line terminal (OLT) and multiple optical network units (ONUS) wherein each ONU is enabled to send a signal only within a time period enabled for the ONU, the OLT (or a system installed therein) identifies a defective one of the ONUs. For each of a given series of time periods, the OLT measures an optical reception level of an optical fiber signal in the time period. The OLT stores, in advance, in a table at least the reception level of a received signal from each ONU in association with the ONU. The reception level is measured in a normal state where signals from the ONUs are exclusively received. For each of the given series of time periods, the OLT decides whether a signal from one of the ONUs associated with the time period is exclusively received with no collision with any other signal.