Abstract: A relaying method includes a request packet generation operation generates a request packet for requesting a connectivity check for all communication routes between said receiver and said transmitter, a request packet transmission operation transmits a generated request packet to a relay, a route information addition operation adds information representing the router itself to the received request packet as route information, a request packet forwarding operation forwards the request packet to which said route information has been added to each of all the communication routes between said receiver and said relay, a response packet generation operation has been transcribed, a response packet transmission operation in which said receiver transmits the generated response packet to said transmitter via said relay, a response packet forwarding operation forwards the received response packet to said transmitter, and a route information output operation outputs the route information included in the received response

Abstract: When a decryption-key request is transmitted from a client computer to a management server via a network apparatus, the network apparatus instead of the client computer adds location information to the decryption-key request. When the decryption-key request reaches the management server, location information stored therein is compared with location information associated with the decryption-key request. When the two pieces of the location information are the same, a decryption key is transmitted to the client computer. Thus, only when the management server receives the decryption-key request via the network apparatus which adds the specific location information to the decryption-key request, the management server transmits the decryption key to the client computer. This allows the encrypted data to be accessed within a specific area.

Abstract: A network includes a plurality of exchanges and a service station which carries out network services. Each exchange of the plurality of exchanges and the service station are connected through a call control signal line. Respective exchanges of the plurality of exchanges are connected through circuits. Each exchange of the plurality of exchanges includes a virtual-index capture processing portion which captures a virtual circuit identification index, and the exchange specifies the virtual circuit identification index and makes a call-out request to the service station.