Abstract: A system containing a visualization application which enables the user or other user to obtain information about various types of transactions involving the respective activities of the components. The user selects filtering criteria that identify various types of transactions performed on each network component from the visualization application and the visualization application uses these criteria in compiling the appropriate records from the network information files. The visualization application then forms the data that represent the records that meet each selected criterion and stores the data in a local file. Thereafter, the user may view the network activity through the visualization application which displays a map of the network and overlays the map with graphical moving images that represent the data for each selected criterion. The graphical images change with time to reflect changes in the underlying data.

Abstract: In one embodiment, a protected switching provider edge (S-PE) and a backup S-PE may be operated, where the protected S-PE has at least one multi-segment pseudowire (MS-PW) and is between a first and second provider edge (PE) on the MS-PW. To protect the protected S-PE, the first and second PE may be informed of the backup S-PE and a backup label to reach the second and first PE, respectively, via the backup S-PE to remain on the MS-PW. Upon detecting loss of connectivity with the protected S-PE, the first and/or second PE may forward packets of the MS-PW to the backup S-PE with the corresponding backup label to reach the second or first PE, respectively, on the MS-PW.

Abstract: In one embodiment, an initiating maintenance end point (MEP) may transmit a lock message to lock a circuit traversing one or more maintenance intermediate points (MIPs) between the initiating MEP and an end MEP. The initiating MEP may then transmit an in-band packet containing a loopback request to a particular MIP along the circuit using a particular time-to-live (TTL) value in the packet to reach the particular MIP. Upon receiving the packet at the particular MIP, and in response to determining that the TTL has expired, the particular MIP inspects the packet to discover the loopback request, and correspondingly operates in a loopback mode.

Abstract: In one embodiment, a connection verification (CV) message is initiated from an initiating maintenance end point (MEP) for an MPLS LSP, the CV message carried in a packet having a time-to-live (TTL) value of 1. Each maintenance intermediate point (MIP) along the MPLS LSP receives the packet and decrements the TTL, and in response to determining that the TTL equals 0, examines a payload of the packet to determine that the packet carries the CV message. The MIP may then append its MIP ID to a route record field of the payload having any previous MIP IDs of upstream MIPs, and forwards the CV message downstream along the MPLS LSP in a packet having a TTL value of 1. The end MEP receives the CV message, and sends a CV reply having the route record field with MIP IDs and an end MEP ID to the initiating MEP.

Abstract: In one embodiment, a first node may send an out-of-band message to a second node to request that the second node initiate an in-band echo request for a specified tunnel, e.g., toward one or more third nodes. Upon receiving the in-band echo request, one or more responding nodes (e.g., generally the third nodes) may send a response to the first node. This “directed echo request” technique may also be used in conjunction with a “reverse traceroute” technique.

Abstract: In one embodiment, a method generally includes identifying at a local Virtual Private LAN Service Provider Edge (VPLS PE) device whether remote VPLS PE devices are configured for operation as a Provider Backbone Bridge (PBB), negotiating pseudowire connections with the remote VPLS PE devices based on identification of the remote VPLS PE device configuration, receiving a frame destined for one of the remote VPLS PE devices, and transmitting the frame in a format compatible with the remote VPLS PE device. The local VPLS PE is configured for operation as a PBB and at least one of the remote VPLS PE devices is not configured for operation as a PBB. An apparatus for use in mixed mode VPLS network is also disclosed.

Abstract: A method of forwarding data in a data communications network having a plurality of nodes comprises the steps, performed at a repairing node, of computing the repair path around a network component to a target node and forwarding data along the repair path. The computing step comprises the step of computing an intermediate node reachable by the repairing node and from which the target node can be reached. The forwarding step includes the step of constructing a Multi-Protocol Label Switching (MPLS) packet for forwarding to the intermediate node.

Abstract: A method and system for finding shared risk diverse paths is disclosed. The method includes receiving route information at a node and running a shortest path algorithm to identify a first path. A shared risk metric is assigned to links and nodes with the first path. The method further includes running the shortest path algorithm with the shared risk metrics assigned to identify a second path and comparing the first and second paths. New shared risk metrics are assigned to links and nodes in the second path if the first and second paths are not diverse. The second path then becomes the first path and the algorithm is repeated.

Abstract: In a tunnel connecting a source node to a destination node, data transfer for the tunnel is enabled through a first path. The data transfer is enabled by reserving resources in intermediate nodes in the first path between the source node and the destination node. Data transfer for the tunnel may be switched from the first path to a second path by reserving resources in intermediate nodes in the second path. If an intermediate node in the second path is shared by the second path and the first path, the resources reserved by the first path are shared by the second path. if an intermediate node in the second path is not shared by the first path, resources are reserved by the second path. After resources are reserved in the second path and data transfer is enabled in the second path, data transfer for the tunnel is switched to the second path.

Abstract: Improved detection of specific BFD LSP path failures is herein disclosed. The improved detection described herein allow for faster fault isolation of a failure along a LSP path, which in turn may allow for faster repair of the failure. When opening a BFD session with a LSP egress node, the LSP ingress node provides the LSP egress node a path descriptor along with the BFD Discriminator. If a BFD failure is detected at the LSP egress node, the LSP egress node can signal an alarm that includes a full description of the path.

Abstract: A network communications tunnel is established by assigning a unique label to each communications link between adjacent nodes in a pre-defined network path. A node's unique label is used to forward a data packet to the adjacent node in the pre-defined path. The unique labels for all the nodes in the pre-defined path are stored by each node in the tunnel. A bypass tunnel to bypass a node in the pre-defined path may be established to reroute data packets around a failed communication link in the tunnel. The bypass tunnel may be established before the communication link failure providing fast tunnel restoration.

Abstract: In one embodiment, a first node may send an out-of-band message to a second node to request that the second node initiate an in-band echo request for a specified tunnel, e.g., toward one or more third nodes. Upon receiving the in-band echo request, one or more responding nodes (e.g., generally the third nodes) may send a response to the first node. This “directed echo request” technique may also be used in conjunction with a “reverse traceroute” technique.

Abstract: A technique for multiple path forwarding of label-switched data traffic in a communication network across multiple paths such that traffic associated with a particular label-switched path (LSP) is forwarded on the same path in the network. An incoming label associated with a packet is used to select an Equal Cost Multiple Path (ECMP) technique that is used to identify an interface among a plurality of interfaces on which the packet may be forwarded. An incoming label associated with the packet is used to identify an outgoing label for the packet as well as the plurality of interfaces on which the packet may be forwarded. A label in the packet's label stack is hashed to produce a hash value. The hash value is then used to identify an interface from the plurality of interfaces on which the packet is forwarded. The outgoing label is placed in the packet and the packet is forwarded on the identified interface.

Abstract: A method for processing token identifiers for Layer 3 (L3) control channels when encapsulated in a tunneling protocol. Rather than encapsulating an L3 control channel with a secondary L3 (or Layer 4 ‘L4 ’) header, a generic (non-Layer 3 header) identifier, or token identifier, is used to encapsulate the control channel. For example, the token identifier may be a simple bit pattern that does not require a complex, confusing or redundant IP/UDP routing table lookup. Instead, the token identifier simply alerts the forwarding entity that local processing of the packet's data is required (e.g., that the packet contains control channel data).

Abstract: In a tunnel connecting a source node to a destination node, data transfer for the tunnel is enabled through a first path. The data transfer is enabled by reserving resources in intermediate nodes in the first path between the source node and the destination node. Data transfer for the tunnel may be switched from the first path to a second path by reserving resources in intermediate nodes in the second path. If an intermediate node in the second path is shared by the second path and the first path, the resources reserved by the first path are shared by the second path. if an intermediate node in the second path is not shared by the first path, resources are reserved by the second path. After resources are reserved in the second path and data transfer is enabled in the second path, data transfer for the tunnel is switched to the second path.

Abstract: A technique dynamically restores original attributes of a Traffic Engineering La-bel Switched Path (TE-LSP) that are provided in a source domain for a destination domain when traversing one or more intermediate domains that may translate the TE-LSP attributes in a computer network. According to the novel technique, a head-end node requests an interdomain TE-LSP having one or more original TE-LSP attributes (e.g., priority, bandwidth, etc.) using a signaling exchange. The head-end node may also request restoration of the original TE-LSP attributes upon entrance into the destination domain. Intermediate domains (e.g., border routers of the domains) receiving the request may translate the original TE-LSP attributes into corresponding intermediate domain TE-LSP attributes. When the request reaches the destination domain, the intermediate domain TE-LSP attributes of the requested TE-LSP are restored into the original TE-LSP attributes.

Abstract: In a tunnel connecting a source node to a destination node, data transfer for the tunnel is enabled through a first path. The data transfer is enabled by reserving resources in intermediate nodes in the first path between the source node and the destination node. Data transfer for the tunnel may be switched from the first path to a second path by reserving resources in intermediate nodes in the second path. If an intermediate node in the second path is shared by the second path and the first path, the resources reserved by the first path are shared by the second path. If an intermediate node in the second path is not shared by the first path, resources are reserved by the second path. After resources are reserved in the second path and data transfer is enabled in the second path, data transfer for the tunnel is switched to the second path.

Abstract: A method for finding shared risk diverse paths is disclosed. The method includes receiving route information at a node and running a shortest path algorithm to identify a first path. A shared risk metric is assigned to links and nodes with the first path. The method further includes running the shortest path algorithm with the shared risk metrics assigned to identify a second path and comparing the first and second paths. New shared risk metrics are assigned to links and nodes in the second path if the first and second paths are not diverse. The second path then becomes the first path and the algorithm is repeated.

Abstract: A method of forwarding data in a data communications network having a plurality of nodes comprises the steps, performed at a repairing node, of computing the repair path around a network component to a target node and forwarding data along the repair path. The computing step comprises the step of computing an intermediate node reachable by the repairing node and from which the target node can be reached. The forwarding step includes the step of constructing a Multi-Protocol Label Switching (MPLS) packet for forwarding to the intermediate node.

Abstract: A network communications tunnel is established by assigning a unique label to each communications link between adjacent nodes in a pre-defined network path. A node's unique label is used to forward a data packet to the adjacent node in the pre-defined path. The unique labels for all the nodes in the pre-defined path are stored by each node in the tunnel. A bypass tunnel to bypass a node in the pre-defined path may be established to reroute data packets around a failed communication link in the tunnel. The bypass tunnel may be established before the communication link failure providing fast tunnel restoration.