Packet transmitting apparatus, packet receiving apparatus, communication system, and packet communication method

A packet receiving apparatus comprising:

• a packet receiving unit which receives a packet having a preassigned sequence number from a transmitting apparatus;
• a receive buffer which stores said received packet;
• a transmitted-packet indication information receiving unit which receives from said transmitting apparatus, separately from said packet, transmitted-packet indication information that indicates said packet transmitted by said transmitting apparatus;
• and
• a packet reordering unit which retrieves from said receive buffer said packet indicated by said transmitted-packet indication information, and which reorders said packet in accordance with said sequence number.

A packet communication method comprising:

• transmitting a packet having a preassigned sequence number from a packet transmitting apparatus to a packet receiving apparatus;
• said packet transmitting apparatus generating transmitted-packet indication information that indicates said packet transmitted by said packet transmitting apparatus;
• and
• said packet transmitting apparatus transmitting said transmitted-packet indication information to said packet receiving apparatus separately from said packet.