Cisco Technology, Inc.

Gabriele Maria Galimberti

Giovanni Martinelli

Jean-Philippe Vasseur

Ornan A Gerstel

Stefano Piciaccia

Ornan Alexander Gerstel

Walid Wakim

Randy Zhang

David Delano Ward

Clarence Filsfils

Rajiv Asati

Maurizio Gazzola

David Bianchi

Manoj N Kumar

Zafar Ali

Fausto Meli

Anand Girish Parthasarathy

Paolo Sironi

Fabrizio Forghieri

Alberto Arnaldo Tanzi

Valerio Viscardi

Manoj Kumar

Mauro Rudi Casanova

Mauro Brunella

Roberto Gianella

Akshaya Nadahalli

Stefano Aina

Marco Portinari

Loukas Paraschis

Errol Fenton Roberts

Antonello Bonfanti

Humayun Sohel

Domenico La Fauci

Ornan Gerstal

Mauro Rudy Casanova

A method for optical restoration in an optical network is provided. A network controller obtains, from one or more optical nodes of an optical network, at least one failure notification indicating a failure of a primary path between a first node and a second node. The network controller forwards to a first set of optical nodes, data-plane parameters for optical components of the first set of optical nodes. The first set of optical nodes include the first node, the second node, and one or more intermediate nodes, and forms a restoration path for the primary path. The data-plane parameters for the optical components are forwarded in parallel to the first set of optical nodes of the restoration path so as to activate the restoration path in parallel. The network controller switches traffic from the primary path to the restoration path.

Method and system for optical path restoration

In one embodiment, a first optical network device includes a controller, and a first network interface, wherein the first network interface is configured to exchange data with a first layer 3 network device, and the controller is configured to obtain at least one optical circuit attribute including an optical circuit distance and/or an optical circuit latency of a first optical circuit in an optical network, and provide the at least one optical circuit attribute to the first layer 3 network device. Related apparatus and methods are also described.

Enhancing routing metrics

The embodiments disclosed herein provide fast recovery of a network signal path by, in the event of a failure or unacceptable degradation in a signal in the original network path, diverting the optical signal passing through the network to a preselected bypass optical path which is maintained in a warm or operational state. The optical elements on the bypass optical path are available network resources which may, during part or all of the time the bypass path is designated for a node in the primary optical path, be in use to transmit other optical signals in the network. By maintaining the resources in the designated bypass path in a warm or operating state, fast rerouting and recovery of an interrupted signal is possible.

Optical path fault recovery

An interface mapping method includes obtaining, at a network controller, device information of network devices configured to be in communication with each other through an optical network. The network devices include a plurality of colored interfaces that support a range of wavelengths for communication in the optical network. Interface information of the colored interfaces of the network devices is obtained, and optical power information associated with each of the colored interfaces is obtained. Optical power margins for a transmitter interface of the colored interfaces. The transmitter interface is controlled to transmit a power sequence based on the optical power margins, and power readings are obtained from a receiver interface of the colored interfaces. A topology between the colored interfaces is discovered based on the power sequence and the power readings.

Method and system for autonomous discovery of colored interface mappings across routing and optical layers

A method is disclosed for use by a network element coupled with an optical transport network. The method comprises calculating an optical path from a first packet-terminated optical interface of the network element to a second packet-terminated optical interface of a destination network element coupled with the optical transport network, and signaling the optical transport network to create the optical path. The method further comprises creating an Ethernet interface corresponding to the first packet-terminated optical interface, and adding the Ethernet interface to an Ethernet bundle interface. The method further comprises communicating across the optical path using addressing of the Ethernet bundle interface.

Transparent deployment of packet services using optical transport network

In one embodiment, a network server layer provides disjoint channels in response to client-layer disjoint path requests. For example, the network layer can be an optical network, and the client layer may be a packet switching layer (e.g., label switching, Internet Protocol). In one embodiment, a server-layer node receives a client-layer disjoint path request to provide a server-layer channel through a server-layer network. The client-layer disjoint path request includes an identifier corresponding to an existing client-layer path that traverses a current channel through the server-layer network that does not include the server-layer node. The server-layer network determines a particular channel through the server-layer network that is disjoint to the current channel based on route information of the current channel, and then signaling is performed within the server-layer network to establish the particular channel.

Network server layer providing disjoint channels in response to client-layer disjoint path requests

Techniques are presented herein to setup a wavelength on a path from a source node to a destination node. Cross-talk margin information already computed for one or more installed wavelengths is obtained between the source node and destination node. A total margin as a function of the cross-talk margin information is computed. A determination is then made as to whether to perform non-linear impairment validation of the wavelength based on the total margin. These techniques may be generalized to account for coherent and non-coherent portions of a network.

DWDM fast lightpath setup using network status information

Techniques are provided for receiving a connection request at a first network node configured to request a connection from the first network node to a second network node. At the first network node, it is determined if a path to the second network node without an optical regenerator is available for the connection. In response to determining that a path without an optical regenerator is not available, a path to the second network node is determined that has a minimum number of optical regenerators. The connection is set up using the path with the minimum number of optical regenerators.

Selecting an optical path for a new connection with the minimum number of optical regenerators

Techniques and a control architecture (apparatus and logic) are provided for an adaptive hybrid DWDM-aware computation scheme. The architecture is one that is a hybrid of a centralized control scheme and a distributed control scheme that performs adaptive physical impairment computations for an optical network. A central control server is connected to multiple client control devices each of which resides in a node in a dense wavelength division multiplexed (DWDM) optical network, wherein each client control device is part of an optical control plane associated with the optical network. The control server obtains data for path route analysis from the client control devices. The control server then determines optical feasibility of at least one path route from a source node to a destination node from optical parametric information based on the data obtained from multiple client control devices and without real-time communication between the central control server and the multiple client control devices while performing the optical feasibility computations.

Adaptive hybrid optical control plane determination of lightpaths in a DWDM network

Methods and apparatus for efficiently utilizing an optical control plane distinct from an electronic control plane to facilitate the setup of paths in a dense wave division multiplexing network are disclosed. According to one aspect of the present invention, a method includes receiving a probe arranged determine the optical feasibility of a first path, and determining a probability of success associated with the probe. The probability of success indicates a likelihood that the probe will be successfully routed on the first path to the destination, and is associated with a particular wavelength. A second path on which to route the probe is dynamically identified if the probability indicates a low likelihood of successful routing on the first path. Finally, the method includes determining if a notification associated with the probe has been received, and altering the probability of success based on the notification if the notification has been received.

Optimization mechanism for use with an optical control plane in a DWDM network

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 slowly modulated pilot tone in a DWDM network without dedicated hardware for the generation and the diction of the tone.

Mechanism for tracking wavelengths in a DWDM network without specialized hardware

Techniques are provided for detecting at a controller associated with a physical layer of a network an occurrence of a failure within the physical layer of the network. In response to detecting the failure, the controller sends messages to at least first and second nodes in a transport layer of the network, where the messages are configured to indicate normal operations in the physical layer so as to prevent execution of transport layer protection processes for a period of time.

Smart protection escalation mechanism prevention

An optical control plane (OCP) distinct from an electronic control plane helps the setup of path routes in a DWDM network. The OCP determines the optical feasibility of any path route selected by the electronic control plane, such as operated under GMPLS protocol, and asks the electronic control plane for another path route if the optical feasibility is determined to be negative. The OCP can be set in a server or distributed across the nodes of the network.

Growing community of inventors

Bovisio Masciago, Italy

Gabriele Maria Galimberti