Embodiments include a method, system, and computer program product for managing data flows in a network. A software-defined network controller obtains one or more attributes associated with one or more devices, such as physical layer devices. The obtained attribute(s) are stored in a table. A flow of data in the network is controlled based on the table.

A transmission start time correction method of a WDM/TDM-PON system includes: a completion instruction procedure in which a station-side subscriber accommodation apparatus issues an instruction using a downstream signal for instructing a subscriber apparatus to perform wavelength switching, the downstream signal including a transmission start time of an upstream signal indicating completion of the wavelength switching of the subscriber apparatus, the upstream signal being transmitted by the subscriber apparatus after the wavelength switching; an instruction completion transmission procedure in which the subscriber apparatus transmits the upstream signal indicating the completion of the wavelength switching at a wavelength after switching at the instructed transmission start time after the wavelength switching is completed in accordance with the instruction; and a transmission start time correction procedure in which the station-side subscriber accommodation apparatus measures a reception time of the upstream signal indicating the completion of the wavelength switching received after the wavelength switching and sets a time obtained by adding a time twice a time difference between a reception time of the upstream signal indicating the completion of the wavelength switching assumed before the wavelength switching and a reception time of the upstream signal indicating the completion of the wavelength switching received after the wavelength switching to the transmission start time of the upstream signal before the wavelength switching as a new transmission start time.

A method for establishing or switching an optical transmission path in order to transmit an optical signal includes the following steps: in a first step, segment optical switching identifier information is detected and determined by a segment destination optical node; and in a second step, the segment destination optical node is controlled such thatdepending on determined content of the segment optical switching identifier informationeither a first output port or a second output port is selected regarding establishing or switching the optical transmission path.

A matrix M indicating a minimum number of all optical paths between pairs of nodes may be generated in one embodiment using an algorithm for transitive closure. In various embodiments, different algorithms and methods may be used to generate matrix M. Once a convergent matrix M has been generated that attains transitive closure, any corresponding reachability matrix RM^a may be obtained from matrix M in a computationally efficient manner. Matrix M may be used to determine groups of potential regenerator placements and obtain end-to-end optical paths by selecting desired sequences of regenerators.

The present application provides a wavelength configuration method for a multi-wavelength passive optical network, which includes: scanning, by an ONU, a downstream receiving wavelength, and receiving, downstream wavelength information of each downstream wavelength channel that is broadcast by an OLT separately through each downstream wavelength channel of a multi-wavelength PON system; establishing, by the ONU, a downstream receiving wavelength mapping table, where an entry of the downstream receiving wavelength mapping table includes downstream receiving wavelength information, drive current information of a downstream optical receiver and receiving optical physical parameter information of the ONU; selecting, by the ONU, one downstream wavelength from the downstream wavelength information broadcast by the OLT, and setting, according to the drive current information of the downstream optical receiver recorded in a related entry of the downstream receiving wavelength mapping table, an operating wavelength of the downstream optical receiver to the selected downstream wavelength.

A method for bandwidth map update includes: after receiving a bandwidth report carried by a control frame, a master node newly establishing a bandwidth map, newly establishing a resource state table, and setting all resource states in the newly established resource state table to be available; adding a cross-master node transport channel drop allocation structure of the newly established bandwidth map in accordance with a cross-master node transport channel add allocation structure of a bandwidth map to be updated, and updating the resource state table; according to the bandwidth report carried by the control frame, allocating a wavelength and an optical burst timeslot one by one to a current bandwidth request, adding wavelengths and optical burst timeslots to the newly established bandwidth map, generating a new bandwidth map, and updating the resource state table; and distributing the control frame carrying the new bandwidth map to slave nodes hop by hop.

Data center network architectures, systems, and methods that can reduce the cost and complexity of data center networks. Such data center network architectures, systems, and methods employ physical optical ring network and multi-dimensional network topologies and optical nodes to efficiently allocate bandwidth within the data center networks, while reducing the physical interconnectivity requirements of the data center networks. The respective optical nodes can be configured to provide various switching topologies, including, but not limited to, chordal ring switching topologies and multi-dimensional chordal ring switching topologies.

A transmission start time correction method of a WDM/TDM-PON system includes: a completion instruction procedure in which a station-side subscriber accommodation apparatus issues an instruction using a downstream signal for instructing a subscriber apparatus to perform wavelength switching, the downstream signal including a transmission start time of an upstream signal indicating completion of the wavelength switching of the subscriber apparatus, the upstream signal being transmitted by the subscriber apparatus after the wavelength switching; an instruction completion transmission procedure in which the subscriber apparatus transmits the upstream signal indicating the completion of the wavelength switching at a wavelength after switching at the instructed transmission start time after the wavelength switching is completed in accordance with the instruction; and a transmission start time correction procedure in which the station-side subscriber accommodation apparatus measures a reception time of the upstream signal indicating the completion of the wavelength switching received after the wavelength switching and sets a time obtained by adding a time twice a time difference between a reception time of the upstream signal indicating the completion of the wavelength switching assumed before the wavelength switching and a reception time of the upstream signal indicating the completion of the wavelength switching received after the wavelength switching to the transmission start time of the upstream signal before the wavelength switching as a new transmission start time.

A processing of data for the management of the placement on standby of a client terminal connected to an operator terminal of an access network, the method comprising, in said client terminal, the following steps: a) determining a policy for placing the client terminal on standby, b) monitoring a client interface of said client terminal, disposed between said client terminal and a part of a local network situated downstream of said client terminal, c) monitoring an access network interface of said client terminal, disposed between said client terminal and said operator terminal.

Validating a path in an optical layer of a communications network, for client traffic having an associated service level, involves setting an optical quality margin according to the service level associated with that client traffic. The optical quality margin indicates how close an estimated optical quality of the path can approach a level which produces a threshold error rate. This margin is used to check whether the estimated optical quality is within the optical quality margin set according to the client traffic service level. Making the optical quality margin dependent on client traffic service level, can enable increased optical reach. This can give more flexibility in path selection and enable better matching to service levels of client traffic.