Abstract: A regulation apparatus for ATM cell delay variation includes a variation regulating buffer for temporarily storing cells transferred thereto, a variation waiting timer for controlling a waiting time which extends from reception of the first cell to read-out of cells from the buffer, a read-out timer for controlling intervals at which cells are read from the buffer, a latest cell preservation memory for storing the latest cell transferred from a VPI/VCI demultiplexing unit and, a selector for selecting a cell stored in the buffer or in the memory to transfer the selected cell to a cell reproduction unit.

Abstract: In an apparatus, there are provided an IP transmitting and receiving unit for transmitting and receiving an IPv4 packet and an IPv6 packet; an IP header converting unit for performing a mutual conversion of the IPv4 packet and the IPv6 packet by an IP header conversion; a DNS substituting unit for receiving a domain information capturing request sent from an IPv4 terminal or an IPv6 terminal and substituting its process; an IPv4 address capturing unit for capturing an IPv4 address from a DHCP server; and an IP address conversion information holding unit for holding an IPv6 address of the IPv6 terminal and the IPv4 address captured by the IPv4 address capturing unit in correspondence to each other. Thus, a communication with the IPv4 terminal can be executed without preliminarily fixedly allocating the IPv4 address to the IPv6 terminal.

Abstract: A translator for coupling a first network such as an internet protocol version 4 (IPv4) and a second network such as an internet protocol version 6 (IPv6) having different addressing architectures for IP addresses due to a difference in version or the like so as not to exhaust the IP addresses of one of the two networks, a network system using the translator, and a network coupling method therefor are provided. When a packet is transferred from the IPv6 network to the IPv4 network, the translator assigns any of a plurality of previously prepared IPv4 addresses to an IPv6 address stored in a source storing field of the IPv6 packet. The assigned address is stored in a source storing field of an IPv4 packet. A packet translation unit is provided for assigning the foregoing IPv6 address to an IPv4 address stored in a destination storing field of the IPv4 packet, when a packet is transferred from the IPv4 network to the IPv6 network, and for storing this address in a destination storing field of the IPv6 packet.

Abstract: A regulation apparatus for ATM cell delay variation includes a variation regulating buffer for temporarily storing cells transferred thereto, a variation waiting timer for controlling a waiting time which extends from reception of the first cell to read-out of cells from the buffer, a read-out timer for controlling intervals at which cells are read from the buffer, a latest cell preservation memory for storing the latest cell transferred from a VPI/VCI demultiplexing unit and, a selector for selecting a cell stored in the buffer or in the memory to transfer the selected cell to a cell reproduction unit.