Communication system, control apparatus, communication method, and program

摘要

When calculating a forwarding path for a packet, a control apparatus determines a second node on the exit side of the packet forwarding path and an output port thereof. Next, the control apparatus sets in a second node located upstream of the first node on the packet forwarding path a packet handling operation for writing flow identification information associated with the output port in a packet header field not to be referred to when the first node forwards the packet and rewriting address information in the packet header such that the packet arrives at the second node on the exit side, and then causing the packet to be forwarded. A packet handling operation for causing the packet with the flow identification information given thereto to be transmitted from the port associated with the flow identification information is set in the second node on the exit side.

主权项

1. A communication system, comprising:
a first node that forwards a received packet by referring to an address table associating a port(s) of an own first node(s) and address information of a node(s) to which the received packet may be forwarded from the port(s); at least one second node disposed on each of an entry side and an exit side of a packet forwarding path that passes via the first node(s), each of the at least one second node comprising a packet processing unit that processes the received packet according to a packet handling operation associating a process to be applied to the packet and a matching rule for identifying the packet to which the process is to be applied; and a control apparatus that sets the packet handling operation in each of the second nodes; the control apparatus comprising: a path search unit that determines a packet forwarding path, at least one second node located on the exit side of the packet forwarding path, and an output port of the second node located on the exit side of the packet forwarding path in order to transmit the packet belonging to a new flow to a target address, based on a request from the at least one second node located on the entry side; and a packet control command generation unit, the packet control command generation unit setting in one of the at least one second node located upstream of the first node on the packet forwarding path a packet handling operation for writing flow identification information associated with the output port in a field of a packet header not to be referred to when the first node forwards the packet and rewriting address information in the packet header such that the packet arrives at the second node on the exit side, and then causing the packet to be forwarded, the packet control command generation unit setting in the second node located on the exit side of the packet forwarding path a packet handling operation for causing the packet with the flow identification information given thereto to be transmitted from the port associated with the flow identification information.