Abstract: This invention has as its object to provide an ATM relay device which attains high-speed, large-capacity packet relaying by distributing the load on an IP forwarding unit without having to improve the operation speed, processing performance, and the like of an IP forwarding function. This invention has an ATM switch core (111) for distributing input ATM cells to corresponding ones of a plurality of output ports on the basis of their destination information. A plurality of IP forwarding units (120-1 to 120-n), which are provided in correspondence with the respective output ports of the ATM switch core (111) and have unique forwarding processing functions, execute predetermined forwarding processes for packets obtained by reassembling ATM cells input via the respective output ports.

Abstract: Header data representing a frame form and a protocol is divided into each two bytes to set a plurality of search sequences, and, for each sequence, an entry comprising the divided two bytes serving as Key Data, a search identifier comprising Group number and Sequence number, and associative data representing the contents of search control is created. The entry is preliminarily registered in a protocol table. Each time when frame data is stored in a frame buffer, a search is performed in the protocol table using 2 bytes as a key positioned at a specific position of the frame data by a protocol analysis portion, and the search in the protocol table is repeated until a search is terminated according to the contents of the associative data read out from the protocol table by the search.

Abstract: Header data representing a frame form and a protocol is divided into each two bytes to set a plurality of search sequences, and, for each sequence, an entry comprising the divided two bytes serving as Key Data, a search identifier comprising Group number and Sequence number, and associative data representing the contents of search control is created. The entry is preliminarily registered in a protocol table. Each time when frame data is stored in a frame buffer, a search is performed in the protocol table using 2 bytes as a key positioned at a specific position of the frame data by a protocol analysis portion, and the search in the protocol table is repeated until a search is terminated according to the contents of the associative data read out from the protocol table by the search.

Abstract: The present invention aims at making the cut-through trigger variable in accordance with the traffic environment, thereby increasing the cut-through traffic to enhance the efficiency of communication. In the trigger filtering unit (16A), the number of transfers of the hop-by-hop packet meeting each of a plurality of preset trigger conditions is counted. In the processor (15A), the rate of the traffic meeting each of trigger conditions to all the traffics of the hop-by-hop transfer is calculated in accordance with the count value, a trigger condition under which the rate exceeds the threshold value is selected as the cut-through trigger, and it is determined which of the cut-through transfer mode and the hop-by-hop transfer mode should be selected.