Abstract: In a press forming device and a press forming method for press-forming a workpiece that includes a load control region to which a constant load is to be applied, the press forming device includes a die unit that includes an upper die and a lower die that sandwich the workpiece; a slider that holds the upper die; a bolster that holds the lower die; a pressing mechanism that presses the slider toward the bolster at a plurality of pressing points; and one or more support blocks arranged around the die unit, between the bolster and the slider. The support block is arranged farther outward than the pressing points, on a line that extends, in an arrangement direction of the pressing points, from a reference point on an end portion of the load control region.

Abstract: In a ring redundant communication path control method, each of transfer apparatuses periodically transmits an inspection frame for inspecting a communication path, detects a failure of the communication path when the inspection frame is not received for a fixed time, transmits a non-arrival notification frame for notifying that the inspection frame has not arrived yet, and detects a failure of the communication path when the non-arrival notification frame is received.

Abstract: An edge Bridge (2A) executes Ethernet encapsulation. Even when redundant MAC addresses are used in the network of a customer, the MAC address of the customer is not referred to in a backbone network (1). Since forwarding is done on the basis of a MAC address added by the edge Bridge (2A), correct forwarding is possible. Additionally, in the edge Bridge (2A), a Service VLAN ID based on the customer-facing port which has received a customer MAC frame and the VLAN ID in the customer MAC frame is added to the customer MAC frame, thereby building a completely closed network for each customer. The customer can belong to a plurality of Service VLANs through a single customer-facing port and select, by a VLAN ID, a Service VLAN to which he/she should belong.

Abstract: In receiving a MAC (media access control) frame whose destination address is any of a broadcast address, an unknown multicast address and an unknown unicast address, the flooding is reduced by broadcasting the received MAC frame to all the other ports than one that has received the MAC frame. An output control that attains this object is realized by using a destination group identifier (ID) look-up table (2-T1) which enables a look-up of a destination group ID by using, as a key, any one or combination of header information of the MAC frame, a port which received the MAC frame and a service VLAN (virtual local area network) ID corresponding to the MAC frame and a backbone port look-up table (2-T2) which enables a look-up of at least one backbone port which is to transmit or at least one backbone port which is not to transmit by using the destination group ID as a key.

Abstract: In receiving a MAC (media access control) frame whose destination address is any of a broadcast address, an unknown multicast address and an unknown unicast address, the flooding is reduced by broadcasting the received MAC frame to all the other ports than one that has received the MAC frame. An output control that attains this object is realized by using a destination group identifier (ID) look-up table (2-T1) which enables a look-up of a destination group ID by using, as a key, any one or combination of header information of the MAC frame, a port which received the MAC frame and a service VLAN (virtual local area network) ID corresponding to the MAC frame and a backbone port look-up table (2-T2) which enables a look-up of at least one backbone port which is to transmit or at least one backbone port which is not to transmit by using the destination group ID as a key.

Abstract: In a ring redundant communication path control method, each of transfer apparatuses periodically transmits an inspection frame for inspecting a communication path, detects a failure of the communication path when the inspection frame is not received for a fixed time, transmits a non-arrival notification frame for notifying that the inspection frame has not arrived yet, and detects a failure of the communication path when the non-arrival notification frame is received.

Abstract: An edge Bridge (2A) executes Ethernet encapsulation. Even when redundant MAC addresses are used in the network of a customer, the MAC address of the customer is not referred to in a backbone network (1). Since forwarding is done on the basis of a MAC address added by the edge Bridge (2A), correct forwarding is possible. Additionally, in the edge Bridge (2A), a Service VLAN ID based on the customer-facing port which has received a customer MAC frame and the VLAN ID in the customer MAC frame is added to the customer MAC frame, thereby building a completely closed network for each customer. The customer can belong to a plurality of Service VLANs through a single customer-facing port and select, by a VLAN ID, a Service VLAN to which he/she should belong.