Abstract:
A line status monitoring circuit receives a frame through one of a number of lines from another node connected through a redundant transmission channel which is made redundant by the lines. The line status monitoring circuit includes a line-specific check frame monitoring unit. If a line-specific check frame having an added dedicated header corresponding to each of the plurality of lines is received through one of the lines from another node, the line-specific check frame monitoring unit determines whether or not a further line-specific check frame corresponding to a frame for checking which is identical to a frame for checking to which the line-specific check frame corresponds is received through at least a predetermined number of lines within a predetermined time. If the further line-specific check frame is not received in this manner, the line-specific check frame monitoring unit discards the frame.
Abstract:
The present invention, provides an Ethernet transmission apparatus comprising a first and second MEPs provided for each of transmission lines of operational and non-operational systems and for performing the transmission/reception of a frame to be transmitted over each transmission line in a duplexed manner, and a switching processing part for switching the MEP to be used for reception by using ETH-CC which is transmitted at regular intervals, in which the above described first and second MEPs are configured to be able to confirm each other's received content and are adapted to add a continuous sequence number to the ETH-CC when transmitting the ETH-CC, and when the sequence number of the received ETH-CC is smaller than the sequence number of the ETH-CC received by the operational system side, the MEP of the non-operational system side is adapted not to transmit the frame.
Abstract:
An object of the present invention is to provide an operation and administration system that allows location of a failure in a network such as an Ethernet network. For this purpose, the operation and administration system of the present invention is characterized in that: a start point MEP unit 2A on a start point node 1A serving as the start point of an administered section transmits a link trace message (LTM) to an end point MEP unit 2D on an end point node 1D in a predetermined cycle; each of MIP units 3A to 3C existing on a transfer route of the LTM receives the LTM, and relays the LTM to the next node and also transmits a link trace reply (LTR) to the start point MEP unit 2A; the end point MEP unit 2D receives the LTM and transmits an LTR to the start point MEP unit 2A; the start point MEP unit 2A, upon receiving an LTR to the transmitted LTM, retrieves a piece of link trace information with a source ID indicating a source of the received LTR from a link trace DB having registered therein pieces of link trace information each including a source ID indicating a source of an LTR and a reception time of the LTR, and updates the reception time in the retrieved piece of link trace information to the current time.
Abstract:
There is provided a line status monitoring circuit, a node, a communication system, and a failure occurrence determining method which can detect occurrence of a failure in some of redundant lines between nodes. A line status monitoring circuit receives a frame through one of a plurality of lines from another node connected through a redundant transmission channel which is made redundant by the plurality of lines. The line status monitoring circuit includes a line-specific check frame monitoring unit 51. If a line-specific check frame having an added dedicated header corresponding to each of the plurality of lines is received through one of the plurality of lines from another node, the line-specific check frame monitoring unit 51 determines whether or not a further line-specific check frame corresponding to a frame for checking which is identical to a frame for checking which the line-specific check frame corresponds to is received through a predetermined number or more of lines within a predetermined time. Then, if the further line-specific check frame is not received through the predetermined number or more of lines within the predetermined time, the line-specific check frame monitoring unit 51 discards the frame for checking corresponding to the first received line-specific check frame.
Abstract:
Upon producing a topology of a network including a plurality of nodes (L2SW-1 to L2SW-7) connected via the Ethernet, an NSM (101) collects, from each of the nodes, reception result information obtained by continuity check performed by each node, VLAN setting information, and MAC information of a port or ports, and produces the topology of the network for each of VLAN A and VLAN B.
Abstract:
The present invention, provides an Ethernet transmission apparatus comprising a first and second MEPs provided for each of transmission lines of operational and non-operational systems and for performing the transmission/reception of a frame to be transmitted over each transmission line in a duplexed manner, and a switching processing part for switching the MEP to be used for reception by using ETH-CC which is transmitted at regular intervals, in which the above described first and second MEPs are configured to be able to confirm each other's received content and are adapted to add a continuous sequence number to the ETH-CC when transmitting the ETH-CC, and when the sequence number of the received ETH-CC is smaller than the sequence number of the ETH-CC received by the operational system side, the MEP of the non-operational system side is adapted not to transmit the frame.