Routing packets by a router involves establishing a first flow configured for forwarding the packets from a first ingress interface to a first egress interface of the router; determining a condition to modify the first flow; deactivating the first flow; establishing a second flow configured for forwarding the packets from at least one of (1) the first ingress interface to a second egress interface, (2) a second ingress interface to the first egress interface, or (3) a second ingress interface to a second egress interface; and activating the second flow.

A switch node provided with a switch, an input interface and an output interface. The input interface is adapted to couple to a first communication link to receive a first TDM frame having a user payload field containing a first user data from the first communication link, and a frame overhead field containing a first identification. The input interface is configured to validate the first identification in the frame overhead field and reject the first TDM frame responsive to the first identification being invalid, and to forward the first user data to the switch responsive to the first identification being valid. The output interface is adapted to couple to a second communication link. The output interface is configured to receive the first user data from the switch, and to generate a second TDM frame having a second user payload field containing the first user data, and a second frame overhead field containing a second identification that is different from the first identification. The output interface is also configured to transmit the second TDM frame onto the second communication link.

A method, apparatus and computer program product for providing quick designated router transitions in broadcast networks is presented. An Alternate Designated Router (ADR) in a network detects node failure of a Designated Router (DR) prior to other nodes of the network detecting the failure of the DR. In response to the detecting node failure of the DR, the ADR floods the network with a link state packet of a pseudonode within the network. At least one other node of the network detects failure of the DR. The at least one other node computes routes to take into account the failure of the DR by the at least one other node of the network, wherein there is minimal traffic loss since the pseudonodes link state packet is already present before the computing routes takes place.

A method, apparatus, and computer-readable storage medium are disclosed for processing shared risk group (SRG) information in communications networks. The method includes processing, at a first network layer, first network information comprising a plurality of SRG identifiers. The processing includes producing second network information comprising a smaller number of SRG identifiers than that of the plurality of SRG identifiers. The method further includes sending at least a portion of the second network information to the second network layer. The apparatus includes a network interface adapted to send network information comprising SRG information, a processor coupled to the network interface, and a memory coupled to the processor and adapted to store program instructions operable when executed to carry out steps of the method. The storage medium is configured to store program instructions that when executed are configured to cause a processor to carry out steps of the method.

A first device may receive network traffic including a first label. The first label may be an inclusive multicast label associated with a second device. The second device may be a designated forwarder for an Ethernet segment. The first device may determine a second label based on receiving the network traffic including the first label. The second label may be used to route the network traffic to a customer edge device, via a third device, rather than the second device. The third device may be a non-designated forwarder for the Ethernet segment. The first device may provide the network traffic, including the second label, to the third device to permit the third device to provide, via the Ethernet segment, the network traffic to the customer edge device based on the second label when a failure occurs in association with the second device.

A method for failure recovery in a virtual network environment including a virtual network having virtual nodes and virtual links mapped onto substrate nodes and substrate paths, respectively, of a substrate network, the method comprising, in response to an indication of failure of at least one substrate node in the substrate network: re-mapping a virtual node mapped to a failed substrate node to a selected substrate node other than the failed substrate node; and re-mapping a virtual link mapped to a substrate path that involves the failed substrate node to a substrate path that does not involve the failed substrate node; wherein the re-mapping is carried out to achieve at least one re-mapping objective.

Graceful restart in routers having redundant routing facilities may be accomplished by replicating network (state/topology) information.

Frames received at a redundant port connecting a node to a communications network are identified by the frames including a sequence number associated with a source. A frame is received at the redundant port from a source. A newest sequence number of frames received from the source at the node is determined. A window of frames from the source is determined by corresponding sequence numbers. The window includes sequence numbers preceding the newest sequence number and associated with reception information of a corresponding frame at the node. The node relays the frame, when a sequence number of the received frame is within the window and the reception information indicates a first reception of the frame at the node.

An RB device creates a primary multicast tree and a corresponding backup multicast tree, and determines whether the primary multicast tree for forwarding traffic fails or not, according to a received first LSP packet; when the primary multicast tree fails, the RB device forwards the traffic using the backup multicast tree.

A protection switching method and apparatus using operator's command in a dual-node interconnection-based protection switching. An operation method of a third end node receives an operator's command for selecting one of a working path and a protection path in a protection domain, receives information about an isolation status of a second end node and the third end node in an adjacent recovery domain connected through the second end node connected to the working path and the third end node connected to the protection path, determines whether to connect to the second end node based on information about the isolation status, delivers traffic to a path determined based on the operator's command and whether to connect to the second end node, and transfers, to the second end node, information about a connectivity decision including whether to connect to the second end node.