Abstract: A mobile communication terminal 10 is assembled by a user incorporating an arbitrary desired function module 31, 32, 33 into a core module 20. When assembling the terminal, it is not possible for the core module 20 to know what type of function module is being incorporated in advance, but it is possible to ascertain the type of function module that has been incorporated by using identification information notified to the connection module control means of the core module 20 via the core module communication processing section of the function module 31, 32, 33 and the inter-module communication processing section of the core module 20. The core module 20 therefore implements a function appropriate to the users needs by appropriately controlling that function module. Therefore, it is possible to make effective use of resources, as well as reducing the burden placed on a user when upgrading or adding functions, to meet the diverse needs of the user.

Abstract: A mobile communication terminal having a digital camera and which is comprised of a first section and a second section. There are four structural states realized by folding up of the mobile communication terminal and rotation of a display section with respect to a base section of the second section. In each of the four structural states, the mobile communication terminal automatically allocates operations modes of camera mode and non-camera mode. Also, the mobile communication terminal can automatically change the operating mode as required.

Abstract: A network system is comprised of a learning management program in a CPU to send and receive a learning frame, a frame transfer unit which transfers a learning frame, and a learning frame transmission management unit which judges whether learning has completed or not.

Abstract: A node of a spanning tree system operating on a network connecting a plurality of nodes, comprises two transfer units which determines an output destination port, based on the destination MAC address of an input frame, two tree managers which configures a spanning tree according to a spanning tree protocol, and a virtual port of connecting the tree manager and the transfer unit.

Abstract: In frame transfer in a network for transferring an Ethernet frame sent from a source on the network to a predetermined destination, to an applied Ethernet frame, an expansion tag containing information about forwarding to an egress edge node to a host as a destination is added to make an expansion frame, and each node on the network relays the data frame based on the forwarding information of the added expansion tag to transfer the frame to the egress edge node.

Abstract: A node that configures a spanning tree over a network to which a plurality of nodes are connected generates a tree after a cost change using another LAN while continuing to operate the tree that existed before the change, and switches the tree that is used for forwarding after the new tree has been stable.

Abstract: A node to relay the Ethernet frame provided with means to insert, in the relay process of the frame, two or more VLAN tags into the frame at a time and to remove the inserted VLAN tags wherein a TTL area to show the frame survival time is provided in the VLAN tag to be inserted to the frame so that whether the survival time has been elapsed or not is checked by the value in the TTL area and the frame after elapse of the survival time is discarded without being relayed.

Abstract: In a congestion control system for congestion controlling communications on a network, a congestion control node has a congestion detection part for detecting a congestion level of the communications in the congestion control node in question and a congestion notifying part for notifying other congestion control nodes on the network of congestion information detected by the congestion detection part. The congestion control node further has a part for receiving the congestion information from the other congestion control nodes and a congestion flow estimating part for estimating, with reference to the congestion information and a routing table for designating a transfer path to destination, a flow having the congestion level that is not less than a predetermined level in the transfer path to the destination.