Patent ID: 8027352

Claim:
A gateway apparatus for performing transfer control of frame data between communication channels, the gateway apparatus comprising: a first storage portion having transmission storage portions and reception storage portions, each of the transmission storage portions and the reception storage portions being provided for each of the multiple communication channels; a routing unit that retrieves frame data from a reception storage portion and that divides the frame data into frame data to be sent to a controller and the frame data to be sent to a hardware search engine according to the reception storage portion from which the frame data is retrieved, the frame data being sorted according to an identification number respectively recorded in the frame data and being respectively stored in the reception storage portion; a time stamp adding unit for adding time stamp information to the frame data sent to the hardware search engine; the controller, controlled by software programs, that receives the frame data sent from the routing unit, determines a communication channel among the multiple communication channels being used by a node to which the frame data is sent based on information recorded in the frame data and that transmits the frame data to a transmission storage portion corresponding to the communication channel; the hardware search engine that receives the frame data to which the time stamp is added sent from the time stamp adding unit, that determines a communication channel being used by a node to which the frame data is sent based on information recorded in the frame data and that transmits the frame data to one of the storage regions in a second storage portion corresponding to the communication channel, each of the storage regions being provided for each of the multiple communication channels; and a counting unit that counts the frame data stored in the second storage portion, wherein the controller determines whether the frame data is stored in the second storage portion based on a count value counted by the counting unit, calculates time lag by comparing the time stamp information added to the frame data retrieved from the second storage portion with a current time, compares the time lag with a first threshold value and a second threshold value, deletes the frame data stored in the second storage portion when the time lag exceeds the first threshold value, and transmits the frame data stored in the second storage portion to the transmission storage portions with priority over the frame data sent from the routing unit when the time lag is equal to or less than the first threshold value and is more than the second threshold value.