摘要:
In one embodiment, techniques provide a mechanism for tracking wavelengths in a DWDM network. In particular, embodiments of the present invention also provide for connection tracking using a fast pilot tone in a DWDM network without dedicated hardware for the generation and the diction of the tone.
摘要:
Even though network connections have priorities for reconnection and preemption of other connections upon a failure, these priorities are fixed based on the Service Level Agreement (SLA) between the Service Provider and the customer, and do not depend on the actual outage time, or downtime, during the operation of the network. Only a fixed pecking order for reconnection is guaranteed. Therefore they cannot ensure the outage a connection which experiences downtimes limited to the SLA. With the present invention, the priorities of the network connections are determined responsive to the failures of the network connections. The priorities of the network connections can also be determined responsive to the permitted downtime of the connections to better meet the SLA of the connection. Another factor in varying a network connection priority can be the expected downtime of a connection.
摘要:
Methods and apparatus for managing an optical network using pilot tones are provided. One method includes selecting an optical path having a plurality of nodes from a database defining an expected optical network. A detected list of pilot tones associated with each node of the selected optical path is generated. An expected list of pilot tones associated with each node of the selected optical path is generated. The detected and expected lists are compared to identify any mismatched nodes.
摘要:
A communication network comprising at least one first terminal, at least one second terminal, a plurality of links, and at least first and second nodes. The first node is bidirectionally coupled to the first terminal through at least a first one of the links, and also is bidirectionally coupled to the second terminal through at least a second link and the second node. Preferably, the first node comprises a plurality of communication paths, each of which is coupled at a first end thereof to at least one corresponding first link. Second ends of the communication paths are all coupled to the second link, through a multiplexing device, and route signals between the first and second links. The first node also preferably comprises at least one alternate communication path having a first end coupled through the multiplexing device to the second link, at least one switch that is coupled to the alternate communication path, and a detector for detecting a failure in at least one of the communication paths. A controller is coupled to the detector and the switch. The controller is responsive to the detector detecting a failure in at least one of the communication paths for controlling the switch to couple the alternate communication path to a corresponding first link, thereby enabling a signal to be routed between that first link and the second link through the alternate communication path.
摘要:
In a WDM optical network DML signals are sideband filtered to compensate for chirp with a feedback loop carrying signals from a monitor unit which helps maintain the sideband filter offset from a peak output of the DMLs. Network components with filtering characteristics, such as AWGs, can be used as the sideband filters. The monitor units monitor the Q-factors or BERs of the filtered signals and the sideband offset is maintained by temperature control of the sideband filters with respect to the DMLs.
摘要:
Systems and methods provide very fast protection switching while leaving selected traffic unprotected. When a link fails, only certain pre-selected paths are rerouted at the point of failure. Other traffic is left unprotected or protected at another layer. Signaling of the failure and the rerouting is performed for the link as a whole rather than for the individual paths. Signaling occurs at a first layer of a digital transmission hierarchy while path rerouting switching occurs at a second hierarchical layer above the first layer. In certain implementations, K1/K2 bytes are used in signaling at the optical line layer (OC-n), while only protected High-Order paths (STS) and Low-Order paths (VT) are protected by the protection switch.
摘要:
A switch core is set forth that comprises a plurality of duplex switches that are interconnected with a interconnection fabric to implement, for example, strictly non-blocking operation of the switch core for reciprocal traffic. In one embodiment, an N-way reciprocal switch is implemented. The N-way reciprocal switch comprises a plurality of duplex switches numbering N of at least a 1×(N−1) switch type (e.g., the duplex switches have at least N−1 ports available for connection to implement the interconnection fabric). The interconnection fabric interconnects the plurality of duplex switches so that each duplex switch is connected to every other duplex switch used in the interconnection fabric by a single connection. A similar architecture using switches numbering N of at least a 1×N switch type are also set forth. Still further, a plurality of duplex switches are used to implement an (n,m)-way switch that, in turn, can be used to construct a recursive LM-way switch core and/or recursively expand an existing Clos switch core.