Patent ID: 7042907

Claim:
A packet transfer apparatus which is connected between transmitting and receiving hosts that perform packet communication complying with TCP/IP (Transmission Control Protocol/Internet Protocol), and transfers a packet on the basis of a connection established by exchanging control packets between the transmitting and receiving hosts before start of data packet exchange, comprising: MSS option rewrite means for determining a first maximum segment size used in a transport layer between the transmitting hosts and said packet transfer apparatus on the basis of path information between the transmitting hosts and said packet transfer apparatus in establishing a connection, notifying the transmitting hosts of the first maximum segment size, determining a second maximum segment size used in a transport layer between the receiving hosts and said packet transfer apparatus on the basis of path information between the receiving hosts and said packet transfer apparatus, and notifying the receiving hosts of the second maximum segment size; and packet fragmentation means for, when the first maximum segment size of a connection corresponding to a transfer packet is larger than the second maximum segment size, fragmenting a data part subsequent to a header of a transport layer of a packet received from the transmitting hosts into a plurality of segments in accordance with the second maximum segment size, and transferring to the receiving hosts a fragmented packet assembled by adding a header copied from header information of the received packet to each fragmented segment.