摘要:
A data communications system has a plurality of nodes connected by a plurality of links. A subset of the links and nodes forms a worker path for carrying worker data through the communications system, and a further subset of links and nodes provides a protection path for carrying other data in the absence of a fault in the worker path and for providing an alternative path for the worker data in the event of a fault in the worker path. The alternative path is predetermined prior to the detection of a fault in the worker path.
摘要:
A method, system and network for routing a multiplexed signal through an optical network (1) comprising nodes (A to F) for routing signals along links (2 to 9) of the network (1), each node (A to F) comprising a lower order matrix (100) and/or a higher order matrix (110). Each matrix (110, 120) is capable of switching segments of the multiplexed signal between interfaces (NL5H) of the matrix (110,120), the lower order matrix (110) capable of switching smaller segments comprising fewer channels than the higher order matrix (120). The method comprises allocating a cost to using each interface (NL5H) of each matrix (110, 120), the allocated cost taking into account a relative value of the lower order matrix (110) to the higher order matrix (120) due to the capability of the lower order matrix (110) to switch smaller segments of the multiplexed signal, generating a cost function associated with possible routes for the signal through the network (1) from the allocated costs, and determining a route for the signal through the network (1) by optimizing the cost function. The system and network are arranged to carry out this method.
摘要:
A network arranged to implement label switched paths, comprising: an ingress label edge router (LER), at least one label switching router (LSR), and an egress LER, in which the ingress LER is connected to the egress LER via one or more of the LSRs. In said network the ingress LER is arranged to transmit, in use, a path message for setting up a bidirectional label switched path (LSP) from the ingress LER to the egress LER via at least one LSR in response for a request for such an LSP. The path message is transmitted over the path of the LSP to be created, in which the path message comprises a first parameter indicative of the bandwidth to be assigned to data traversing the LSP in a first, downstream, direction from ingress LER to egress LER and a second parameter indicative of the bandwidth to be assigned to data traversing the LSP in an opposite, upstream, direction, in which the upstream and downstream bandwidths are different.
摘要:
A communication network protection system made up of interconnected networks, at least one of which has an automatic control plane (for example ASTN) among which are terminal interconnecting nodes. With the terminal interconnection nodes, termed primary nodes, are associated corresponding secondary terminal nodes wherein a secondary terminal node is used to realize a protection circuit in case of failure of the associated primary node.
摘要:
A method, system and network for routing a multiplexed signal through an optical network (1) comprising nodes (A to F) for routing signals along links (2 to 9) of the network (1), each node (A to F) comprising a lower order matrix (100) and/or a higher order matrix (110). Each matrix (110, 120) is capable of switching segments of the multiplexed signal between interfaces (NL5H) of the matrix (110,120), the lower order matrix (110) capable of switching smaller segments comprising fewer channels than the higher order matrix (120). The method comprises allocating a cost to using each interface (NL5H) of each matrix (110, 120), the allocated cost taking into account a relative value of the lower order matrix (110) to the higher order matrix (120) due to the capability of the lower order matrix (110) to switch smaller segments of the multiplexed signal, generating a cost function associated with possible routes for the signal through the network (1) from the allocated costs, and determining a route for the signal through the network (1) by optimising the cost function. The system and network are arranged to carry out this method.
摘要:
A network system comprises at least one input TNE (10) and one output TNE (11) interconnected by circuits in the network (20). Each TNE in the protection step comprises a traffic selector (22, 23) switchable between listening to the traffic input from a work circuit (13, 14) and listening to the traffic input from a reset circuit (18, 19) and a Split module (21, 24) allowing sending of a same traffic output either to a work circuit or to a reset circuit. Each TNE comprises in addition an agent (25, 26) termed ASTN agent commanding activation and deactivation of the reset circuit and switching of the traffic selector between work circuit and reset circuit. Each of the two ASTN agents can emit an “Activate” message to command activation of the reset circuit and signal to the other agent completed activation of the reset circuit and a “RevertRequest” message for signaling to the other agent the desire to deactivate the reset circuit previously activated, and a “Revert” message for commanding deactivation of the reset circuit after reception of a “RevertRequest” message sent to it by the other agent.
摘要:
A network system comprises at least one input TNE (10) and one output TNE (11) interconnected by circuits in the network (20). Each TNE in the protection step comprises a traffic selector (22, 23) switchable between listening to the traffic input from a work circuit (13, 14) and listening to the traffic input from a reset circuit (18, 19) and a Split module (21, 24) allowing sending of a same traffic output either to a work circuit or to a reset circuit. Each TNE comprises in addition an agent (25, 26) termed ASTN agent commanding activation and deactivation of the reset circuit and switching of the traffic selector between work circuit and reset circuit. Each of the two ASTN agents can emit an “Activate” message to command activation of the reset circuit and signal to the other agent completed activation of the reset circuit and a “RevertRequest” message for signaling to the other agent the desire to deactivate the reset circuit previously activated, and a “Revert” message for commanding deactivation of the reset circuit after reception of a “RevertRequest” message sent to it by the other agent.
摘要:
A data communications system has a plurality of nodes connected by a plurality of links. A subset of the links and nodes forms a worker path for carrying worker data through the communications system, and a further subset of links and nodes provides a protection path for carrying other data in the absence of a fault in the worker path and for providing an alternative path for the worker data in the event of a fault in the worker path. The alternative path is predetermined prior to the detection of a fault in the worker path.
摘要:
A method of path protection for a connection-oriented packet switched communications network is described using a protection hub in communication with a worker hub via a core protection path. Both the worker hub and the protection hub communicate with at least one provider edge device via a respective worker and protection paths. The method detects a failure in the communications network, indicates the failure to the at least one of the provider edge device, the worker hub, and the protection hub. The method then employs the core protection path if a failure occurs along a worker path is detected, or a worker path and a protection path in parallel if a failure occurs along the core protection path.