Abstract: To efficiently instruct maintenance workers if failure reports having different contents are issued in a short time period. The control part of the maintenance work instruction system, if a failure report is received from a monitored apparatus to which the first timer is not set, sets the first value to the first timer. After that, during a time period until a value of the first timer comes, if a failure report is received from an identical monitored apparatus, the control part of the maintenance work instruction system sets the second value shorter than the first value to the second timer. Then the control part of the maintenance work instruction system aggregates received failure reports during a time period after the first failure report until a lapse of time defined by the first value or a lapse of time defined by the second value in the second timer, whichever comes first.

Abstract: A control apparatus includes: a first control unit that configures a first virtual network by setting control information in a relay apparatus(es); a multicast group management unit that holds a configuration(s) of a multicast group(s) configured by an apparatus(es) connected to the relay apparatus(es); a multicast path calculation unit that calculates a path(s) for transmitting a multicast packet(s) to the apparatus(es) that belongs to the multicast group(s) on the basis of information about a topology representing a connection relationship about the relay apparatus(es); and a second control unit that sets control information instructing forwarding of the multicast packet(s) along the path(s) in the relay apparatus(es).

Abstract: A control apparatus includes: a first control unit that configures a first virtual network by setting control information in a relay apparatus(es); a multicast group management unit that holds a configuration(s) of a multicast group(s) configured by an apparatus(es) connected to the relay apparatus(es); a multicast path calculation unit that calculates a path(s) for transmitting a multicast packet(s) to the apparatus(es) that belongs to the multicast group(s) on the basis of information about a topology representing a connection relationship about the relay apparatus(es); and a second control unit that sets control information instructing forwarding of the multicast packet(s) along the path(s) in the relay apparatus(es).