Abstract: 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.

Abstract: In one embodiment, a particular device within a client-layer network maintains client-layer topology information including server-layer Shared Risk Link Group (SRLG) information of server-layer devices and links in a server-layer network associated with client-layer links and client-layer nodes in the client-layer network. A determination is made to discover if there is an alternative client-layer path to an established client-layer path between a first packet switching device and a second packet switching device if all server-layer resources of any particular server-layer SRLG of a plurality of total server-layer SRLGs associated with the established client-layer path become unavailable. In one embodiment, the plurality of total server-layer SRLGs includes: an SRLG of a same optical node, an SRLG of a same optical fiber, an SRLG of co-located plurality of optical nodes, and/or an SRLG of co-located plurality of optical fibers.

Abstract: A router configured to communicate data with a destination router over an IP path that includes an IP link that uses a first optical path. The router configured to proactively maintain the performance of the communication of data. The router configured to receive a signal to move the communication off of the first optical path, before performance of the first optical path has failed. The router configured to establish a second optical path to the destination router an associate the IP link with the second optical path and move the communication of data with the destination router to the second optical path. The router may optionally be configured to tear down the first optical path. The trigger received by the router may be an indication of a performance degradation of the first optical path or an indication of a router interface used by the IP link being switched into maintenance mode.

Abstract: In one embodiment, a replacement network communications path is determined using dedicated resources of an existing path. One or more network elements in a network determines a new communications path between a first network node and a second network node in the network while an existing communications path is currently configured in the network to carry traffic between the first and second network nodes. The existing communications path includes one or more exclusive physical resources dedicated to the existing communications path. The new communications path includes at least one of said exclusive physical resources dedicated to the existing communications path. One embodiment includes: subsequent to said determining the new communications path, removing the existing communications path from service, and then instantiating the new communications path, with the new communications path including said at least one of said exclusive physical resources.

Abstract: In one embodiment, negotiation is performed between the client-layer (e.g., Layer-3 or Layer-2) network and the server-layer (e.g., optical) network to establish a path through the server-layer network with desired server-layer characteristics. This negotiation may include a first iteration of a client-layer request of one or more first server-layer characteristics followed by a negative server-layer response, and a subsequent iteration of a particular client-layer request of one or more particular server-layer characteristics followed by a positive server-layer response, with said particular server-layer characteristics including at least one relaxed server-layer characteristic of said first server-layer characteristics.

Abstract: A router configured to communicate data with a destination router over an IP path that includes an IP link that uses a first optical path. The router configured to proactively maintain the performance of the communication of data. The router configured to receive a signal to move the communication off of the first optical path, before performance of the first optical path has failed. The router configured to establish a second optical path to the destination router an associate the IP link with the second optical path and move the communication of data with the destination router to the second optical path. The router may optionally be configured to tear down the first optical path. The trigger received by the router may be an indication of a performance degradation of the first optical path or an indication of a router interface used by the IP link being switched into maintenance mode.

Abstract: A router configured to communicate data with a destination router over an IP path that includes an IP link that uses a first optical path. The router configured to proactively maintain the performance of the communication of data. The router configured to receive a signal to move the communication off of the first optical path, before performance of the first optical path has failed. The router configured to establish a second optical path to the destination router an associate the IP link with the second optical path and move the communication of data with the destination router to the second optical path. The router may optionally be configured to tear down the first optical path. The trigger received by the router may be an indication of a performance degradation of the first optical path or an indication of a router interface used by the IP link being switched into maintenance mode.

Abstract: 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.

Abstract: 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.

Abstract: A router configured to communicate data with a destination router over an IP path that includes an IP link that uses a first optical path. The router configured to proactively maintain the performance of the communication of data. The router configured to receive a signal to move the communication off of the first optical path, before performance of the first optical path has failed. The router configured to establish a second optical path to the destination router an associate the IP link with the second optical path and move the communication of data with the destination router to the second optical path. The router may optionally be configured to tear down the first optical path. The trigger received by the router may be an indication of a performance degradation of the first optical path or an indication of a router interface used by the IP link being switched into maintenance mode.

Abstract: Disclosed are, inter alia, methods, apparatus, computer-storage media, mechanisms, and means associated with registration of optical device characteristics of optical network devices with an optical control layer of the optical network for use in establishing compatible connections through the optical network. Especially end network devices and internal network optical devices that regenerate the optical signal register their communication capabilities of their optical interfaces with the optical control layer of an optical network. This registration allows a light path to be established through the optical network which is compatible with the registered capabilities. The optical control layer may be centralized in an optical layer server and/or distributed among optical devices in the optical network, such as on control processors in multiple, optical layer devices.

Abstract: 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.

Abstract: In one embodiment, a particular device within a client-layer network maintains client-layer topology information including server-layer Shared Risk Link Group (SRLG) information of server-layer devices and links in a server-layer network associated with client-layer links and client-layer nodes in the client-layer network. A determination is made to discover if there is an alternative client-layer path to an established client-layer path between a first packet switching device and a second packet switching device if all server-layer resources of any particular server-layer SRLG of a plurality of total server-layer SRLGs associated with the established client-layer path become unavailable. In one embodiment, the plurality of total server-layer SRLGs includes: an SRLG of a same optical node, an SRLG of a same optical fiber, an SRLG of co-located plurality of optical nodes, and/or an SRLG of co-located plurality of optical fibers.

Abstract: In one embodiment, a replacement network communications path is determined using dedicated resources of an existing path. One or more network elements in a network determines a new communications path between a first network node and a second network node in the network while an existing communications path is currently configured in the network to carry traffic between the first and second network nodes. The existing communications path includes one or more exclusive physical resources dedicated to the existing communications path. The new communications path includes at least one of said exclusive physical resources dedicated to the existing communications path. One embodiment includes: subsequent to said determining the new communications path, removing the existing communications path from service, and then instantiating the new communications path, with the new communications path including said at least one of said exclusive physical resources.

Abstract: In one embodiment, notifications of upcoming maintenance activities are provided by network devices, such as to allow packet switching or other optical layer client devices to reroute traffic prior to the occurrence of the traffic affecting event. For example, one such network device includes optical interfaces for coupling with fibers for transporting information using dense wavelength-division multiplexing (DWDM); DWDM switching equipment for cross-connecting wavelengths of the fibers; and a controller configured to inform packet switching or other optical layer client devices whose traffic would be affected by an upcoming event that would disrupt communication on one or more wavelengths on one or more fibers so that the packet switching or other optical layer client devices can reroute traffic that would otherwise go over said one or more wavelengths onto a different path in a network prior to said disruption.

Abstract: Disclosed are, inter alia, methods, apparatus, computer-storage media, mechanisms, and means associated with registration of optical device characteristics of optical network devices with an optical control layer of the optical network for use in establishing compatible connections through the optical network. Especially end network devices and internal network optical devices that regenerate the optical signal register their communication capabilities of their optical interfaces with the optical control layer of an optical network. This registration allows a light path to be established through the optical network which is compatible with the registered capabilities. The optical control layer may be centralized in an optical layer server and/or distributed among optical devices in the optical network, such as on control processors in multiple, optical layer devices.

Abstract: In one embodiment, information is exchanged between independent control planes of different layers in a multilayer network, such as, but not limited to, between a packet switching client-layer network and an optical server-layer network. This exchanged information includes signaling regarding a server-layer communications service, having server-layer characteristics, within the server-layer network for use in communicatively coupling at least two devices of the client-layer network. In one embodiment, the client-layer network specifies at least one of these server-layer characteristics that the server-layer communications service provided by the server-layer network must have. In one embodiment, the server-layer network signal to the client-layer network at least one of these server-layer characteristics of the existing server-layer communications service.

Abstract: Disclosed are, inter alia, methods, apparatus, computer-storage media, mechanisms, and means associated with registration of optical device characteristics of optical network devices with an optical control layer of the optical network for use in establishing compatible connections through the optical network. Especially end network devices and internal network optical devices that regenerate the optical signal register their communication capabilities of their optical interfaces with the optical control layer of an optical network. This registration allows a light path to be established through the optical network which is compatible with the registered capabilities. The optical control layer may be centralized in an optical layer server and/or distributed among optical devices in the optical network, such as on control processors in multiple, optical layer devices.

Abstract: Disclosed are, inter alia, methods, apparatus, computer-storage media, mechanisms, and means associated with registration of optical device characteristics of optical network devices with an optical control layer of the optical network for use in establishing compatible connections through the optical network. Especially end network devices and internal network optical devices that regenerate the optical signal register their communication capabilities of their optical interfaces with the optical control layer of an optical network. This registration allows a light path to be established through the optical network which is compatible with the registered capabilities. The optical control layer may be centralized in an optical layer server and/or distributed among optical devices in the optical network, such as on control processors in multiple, optical layer devices.

Abstract: Efficient methods for rerouting failed channels on to spare channels in a multichannel transmission system are described. One method uses a minimal amount of rerouting to reroute all the channels if one or two line cards fail.