Abstract: Disclosed is a technique which prevents description offensive to public order and morals, included in an electronic mail, from meeting the eyes of a receiver. If an electronic mail message is included in a payload part of a data packet delivered from a communication interface 11-2, a control section 13 of a relay apparatus 10-m determines whether a character string offensive to public order and morals is included in a body text part thereof. If the character string offensive to public order and morals is included therein, the control section 13 generates hiding data by encoding the body text part in a mail body of the original electronic mail message. The control section 13 overwrites a hiding notification character string in the body text part in the original electronic mail message, generates a body text-hidden electronic mail message which describes the hiding data in a content body of a part different from the body text part, and transmits it to a terminal 20-i.

Abstract: Provided is a multicast distribution system which can perform a multicast distribution by selecting a communication path satisfying a communication feature required by a multicast group. A distribution source router (Rs) performs a multicast distribution to routers (R1 to R5) constituting a multicast group based on an application via a mesh virtual network connected to a plurality of routers. When the CPU load ratio and the multicast group communication feature exceed threshold values, the distribution source router updates the number of branches and the depth of the multicast tree which distributes a packet from the router and starts reconfiguration of the multicast tree. When reconfiguring the multicast tree, the distribution source router references a path feature of the mesh virtual network, selects a communication path having a sufficient path feature with a higher priority, and generates a routing table based on the multicast tree.

Abstract: A relay apparatus can easily determine the presence or absence of fabrication in a transmission source electronic mail address of an electronic mail message. The relay apparatus 10-m (m=1, 2, . . . ) obtains a transmission source electronic mail address and trace information from a header field of “From” and a header field of “Received” in a mail header mh of an electronic mail message transmitted to a terminal 20-i (i=1, 2, . . . ) from a mail transfer server apparatus 30-n (n=1, 2, . . . ). Further, in a case where the transmission source electronic mail address and the trace information include a character string of the same domain name, a character string indicating that the transmission source is not fabricated is added to a mail body mb for transmission, and in a case where a character string of the same domain name is not included, a character string indicating that the transmission source is fabricated is added to the mail body mb for transmission.

Abstract: Disclosed is a technique which prevents description offensive to public order and morals, included in an electronic mail, from meeting the eyes of a receiver. If an electronic mail message is included in a payload part of a data packet delivered from a communication interface 11-2, a control section 13 of a relay apparatus 10-m determines whether a character string offensive to public order and morals is included in a body text part thereof. If the character string offensive to public order and morals is included therein, the control section 13 generates hiding data by encoding the body text part in a mail body of the original electronic mail message. The control section 13 overwrites a hiding notification character string in the body text part in the original electronic mail message, generates a body text-hidden electronic mail message which describes the hiding data in a content body of a part different from the body text part, and transmits it to a terminal 20-i.

Abstract: Provided is a multicast distribution system which can perform a multicast distribution by selecting a communication path satisfying a communication feature required by a multicast group. A distribution source router (Rs) performs a multicast distribution to routers (R1 to R5) constituting a multicast group based on an application via a mesh virtual network connected to a plurality of routers. When the CPU load ratio and the multicast group communication feature exceed threshold values, the distribution source router updates the number of branches and the depth of the multicast tree which distributes a packet from the router and starts is reconfiguration of the multicast tree. When reconfiguring the multicast tree, the distribution source router references a path feature of the mesh virtual network, selects a communication path having a sufficient path feature with a higher priority, and generates a routing table based on the multicast tree.