Abstract: In an embodiment, a method comprises determining a set of protected components that are associated with a notifying node; determining a single network repair address for the set of protected components, wherein the single network repair address is for use in response to unavailability of any of the protected components when transmitting network traffic to the notifying node; assigning the single network repair address to each of the protected components; wherein the notifying node is an internetworking device and wherein the method is performed by one or more processors.

Abstract: The embodiments described herein present methods and apparatus for dynamically assigning values in a network. A method includes receiving, at a designated value allocator from a network node, a first broadcast message using a link-state protocol. The method then identifies the first broadcast message as including a request to associate a parameter value to the network node and allocates an assigned parameter value to the network node based on the identification of the request included in the first broadcast message. A message that includes the assigned parameter value is then transmitted to the network node. Other embodiments are described.

Abstract: In one embodiment, two neighboring nodes adjacent to each end-point node of a domain may be associated with a “dual” (a logical structure). A first of the two neighboring nodes may be placed into a first family (and group) of the dual, while a second of the two neighboring nodes may be placed into an opposing second family (and group). Augmentations may then be performed, recursively merging and connecting the duals and/or groups, as well as connecting unplaced nodes to particular duals, families, and groups, according to forced augmentations and/or unforced augmentations where no forced augmentations exist. In the end, it may be determined whether the domain supports dual plane topologies based on whether a solution having one resultant dual with a single group in each opposing family is reached from the recursive augmentations.

Abstract: In one embodiment, micro-loops are avoided in ring topologies of packet switching devices by changing the order of propagation of link state information concerning failed communications between a particular packet switching device and a neighbor packet switching device. In one embodiment, the particular packet switching device communicates link state information of a high cost of the particular communications (e.g., in the direction from particular to neighbor packet switching devices) such that this link state information will propagate towards the particular packet switching device from at least from the furthest packet switching device in the ring topology that is currently configured to forward packets having a destination address of the neighbor packet switching device through the particular packet switching device.

Abstract: Data path processing information is included in the pseudowire layer of pseudowire packets in order to provide information for use in the data path processing of data (e.g., a packet), typically, but not always, included in the payload of the pseudowire packet itself. The pseudowire packet typically includes in corresponding fields: a pseudowire label for identifying a pseudowire type; a pseudowire control word; and payload data. The pseudowire type identifies the structure of the pseudowire control word field and the payload field, including the location of data path meta data, such as in the pseudowire control word field or payload field. This data path meta data identifies one or more attributes for use in processing the payload data.

Abstract: A method is described of constructing a transition route in a data communication network having as components nodes and links. Upon receipt of a transition notification identifying a first component a non-neighboring node constructs a transition route around the first component. In an embodiment, a node performs detecting the first component transition; issuing a transition notification identifying the first component and recognizable by nodes configured to construct a transition route around the first component; and upon expiry of a notification transition period, issuing a transition advertisement recognizable by all nodes on the network.

Abstract: A method is described of constructing a transition route in a data communication network having as components nodes and links. Upon receipt of a transition notification identifying a first component a non-neighboring node constructs a transition route around the first component. In an embodiment, a node performs detecting the first component transition; issuing a transition notification identifying the first component and recognizable by nodes configured to construct a transition route around the first component; and upon expiry of a notification transition period, issuing a transition advertisement recognizable by all nodes on the network.

Abstract: In an embodiment, a method comprises determining a set of protected components that are associated with a notifying node; determining a single network repair address for the set of protected components, wherein the single network repair address is for use in response to unavailability of any of the protected components when transmitting network traffic to the notifying node; assigning the single network repair address to each of the protected components; wherein the notifying node is an internetworking device and wherein the method is performed by one or more processors.

Abstract: In one embodiment, two neighboring nodes adjacent to each end-point node of a domain may be associated with a “dual” (a logical structure). A first of the two neighboring nodes may be placed into a first family (and group) of the dual, while a second of the two neighboring nodes may be placed into an opposing second family (and group). Augmentations may then be performed, recursively merging and connecting the duals and/or groups, as well as connecting unplaced nodes to particular duals, families, and groups, according to forced augmentations and/or unforced augmentations where no forced augmentations exist.

Abstract: Data path processing information is included in the pseudowire layer of pseudowire packets in order to provide information for use in the data path processing of data (e.g., a packet), typically, but not always, included in the payload of the pseudowire packet itself. The pseudowire packet typically includes in corresponding fields: a pseudowire label for identifying a pseudowire type; a pseudowire control word; and payload data. The pseudowire type identifies the structure of the pseudowire control word field and the payload field, including the location of data path meta data, such as in the pseudowire control word field or payload field. This data path meta data identifies one or more attributes for use in processing the payload data.

Abstract: In one embodiment, a clock on a network device is initialized, and then a first timing message is received at the network device from a reference device having a first timestamp indicating when the first timing message was transmitted from the reference device. The network device may then determine and store a one-way delay from the first timestamp to a first time at which the first timing message was received at the network device. In response to restarting the clock, the network device may receive a second timing message from the reference device having a second timestamp indicating when the second timing message was transmitted from the reference device. The network device may then calibrate the clock such that a second time at which the network device received the second timing message is the second timestamp plus the stored one-way delay.

Abstract: Approaches for computing path information to a destination node in a data communications network are described. A data communications network comprises as components nodes and links therebetween and comprising a core subdomain of components and a plurality of non-core subdomains of components and having a common identifier for each non-core subdomain. An apparatus comprises first logic which when executed is operable to receive reachability information for a destination node and an associated identifier; and second logic which when executed is operable to perform a computation of path information for a path in the network to a destination node dependent on a particular identifier of a subdomain associated with the destination node, and to forward data for the destination over the path according to the path information.

Abstract: A method of constructing a repair path around a non-available component in a data communications network having, as components, nodes having a network address and links there between comprises the step, performed at a participating node, of receiving from a notifying node in the network, a notification identifying the notifying node and components through which the notifying node can be reached. The method further comprises the step of deriving, from the notification, a network repair address for use in the event of non-availability of a component identified in the notification. The method further comprises the step of constructing a repair path for the repair address.

Abstract: An apparatus for forwarding data in a data communications network having as components nodes and links therebetween is described. The apparatus is arranged to forward data towards a destination on a label switched path and advertise in a label advertisement to nodes in the network in a label advertisement its label for the label switched path and its label for a repair label switched path for use in the event of non availability of a component in the network. The apparatus is further arranged to advertise to a remote node in the network in a label advertisement additional information for deriving repair label switched path information at the remote node.

Abstract: A method of constructing a repair path around a non-available component in a data communications network is described. The data communications network has, as components, nodes and links therebetween defining a network topology. The non-available component is a member of a shared risk group of components commonly renderable non-available. The method comprises the step, performed at a repairing node, of identifying as a repair target a neighbour component of the non-available component. The method further comprises the step of constructing a repair network topology omitting the shared risk group. The method further comprises the step of constructing a repair path to the repair target in the repair topology.

Abstract: A method is disclosed for determining a repair strategy for a data communication network. The data communication network has as components nodes and links. The method comprises a step of implementing a link repair strategy for an adjacent link to an adjacent node. The method further monitors for a probe packet to the adjacent node and, if such a packet is received, implements a node repair strategy.

Abstract: A method is described for forwarding a tunneled packet in a data communications network. A header of the tunneled packet is removed at a forwarding node neighboring the tunnel end point, and the payload is forwarded.

Abstract: A data processing apparatus is configured for initiating a not-via approach for creating repair path information for a first link between the first network node and a second network node; creating a list of other network nodes that the not-via repair path traverses; creating and storing entries in the FIB identifying repair addresses for the network nodes and that cause (a) packets directed to all addresses normally reachable through the first link to be encapsulated to the second node not via the first node, (b) packets directed to a not-via address that is normally reachable through the first link to be encapsulated to the second node not via the first node, and (c) dropping packets directed to a not-via address that is normally reachable through the first link when the not-via address is in the list; repeating the preceding steps for all other links of the first network node.

Abstract: A method of constructing a repair path around a non-available component in a data communications network having, as components, nodes having a network address and links there between comprises the step, performed at a participating node, of receiving from a notifying node in the network, a notification identifying the notifying node and components through which the notifying node can be reached. The method further comprises the step of deriving, from the notification, a network repair address for use in the event of non-availability of a component identified in the notification. The method further comprises the step of constructing a repair path for the repair address.

Abstract: A method is disclosed for constructing a repair path for multicast data around a non-available component in a data communications network having as components nodes and links therebetween. The method comprises the step performed at a repairing node, of receiving from a notifying node in a network, a notification identifying the notifying node and components through which the notifying node can be reached. The method further comprises the steps of deriving, from the notification, a network repair address for use in the event of non-availability of a component identified in the notification; and constructing a repair path for multicast data for the repair address.