Abstract: In general, techniques are described for providing feedback loops for service engineered paths. A service node comprising an interface and a control unit may implement the techniques. The interface receives traffic via a path configured within a network to direct the traffic from an ingress network device of the path to the service node. The control unit applies one or more services to the traffic received via the path and generates service-specific information related to the application of the one or more services to the traffic. The interface then sends the service-specific information to at least one network device configured to forward the traffic via the path so that the at least one network device configured to forward the traffic via the path is able to adapt the path based on the service-specific information.

Abstract: Techniques are described for detecting failure or degradation of a service enabling technology function independent from an operational state of a service node hosting the service enabling technology function. For example, a service node may provide one or more service enabling technology functions, and service engineered paths may be traffic-engineered through a network to service node network devices that host a service enabling technology function. A monitor component at the service layer of the service node can detect failure or degradation of one or more service enabling technology functions provided by the service node. The monitor component reports detection of failure or degradation to a fault detection network protocol in a forwarding plane of the service node. The fault detection network protocol communicates with an ingress router of a service engineered path to trigger fast reroute by the ingress of traffic flows to bypass the affected service enabling technology function.

Abstract: In one example, a network device receives a packet to be forwarded according to a label switching protocol, determines a service to be performed on the packet by a service network device, sends a label request message to the service network device, wherein the label request message indicates support for labels having a particular length, wherein the particular length is larger than twenty bits (e.g., forty bits), and wherein the label request message specifies the service to be performed on the packet, receives, in response to the label request message, a label mapping message defining a label of the particular length, appends the label to the packet to form a Multi-Protocol Label Switching (MPLS)-encapsulated packet, and forwards the MPLS-encapsulated packet according to the label switching protocol.

Abstract: A method, apparatus and computer program product for providing dynamic routing support for Half-Duplex Virtual Routing and Forwarding (HDVRF) environments. The method, apparatus and computer program function to configure a forwarding Virtual Routing and Forwarding (VRF) table for a router with information to forward incoming packets to a central location within a hub and spoke environment. The method, apparatus and computer program also function to populate a routing Virtual Routing and Forwarding (VRF) table for the router with routing information received from ingress interfaces of the router. The method, apparatus and computer program function further forwards packets received on egress interfaces of the router according to the forwarding VRF table.

Abstract: A novel fast reroute (FRR) technique is provided for quickly and efficiently rerouting selected types of network traffic in response to a node or link failure at the edge of a computer network. According to the technique, the network includes first and second edge devices that function as “FRR mates,” such that network traffic originally destined for one FRR mate may be quickly rerouted to the other without having to wait for conventional network convergence. When an edge device receives rerouted packets originally destined for its FRR mate, the device responds by forwarding only those rerouted packets matching the selected traffic types; rerouted packets that do not match the selected traffic types are dropped or otherwise discarded. The first and second edge devices may be statically configured as FRR mates, e.g., by a network administrator, or they may be configured to automatically detect their compatibility as FRR mates.

Abstract: A method, apparatus and computer program product for providing dynamic routing support for Half-Duplex Virtual Routing and Forwarding (HDVRF) environments. The method, apparatus and computer program function to configure a forwarding Virtual Routing and Forwarding (VRF) table for a router with information to forward incoming packets to a central location within a hub and spoke environment. The method, apparatus and computer program also function to populate a routing Virtual Routing and Forwarding (VRF) table for the router with routing information received from ingress interfaces of the router. The method, apparatus and computer program function further forwards packets received on egress interfaces of the router according to the forwarding VRF table.

Abstract: A method, apparatus and computer program product for providing dynamic routing support for Half-Duplex Virtual Routing and Forwarding (HDVRF) environments. The method, apparatus and computer program function to configure a forwarding Virtual Routing and Forwarding (VRF) table for a router with information to forward incoming packets to a central location within a hub and spoke environment. The method, apparatus and computer program also function to populate a routing Virtual Routing and Forwarding (VRF) table for the router with routing information received from ingress interfaces of the router. The method, apparatus and computer program function further forwards packets received on egress interfaces of the router according to the forwarding VRF table.

Abstract: A system and method are provided for separately distributing edge-device labels and routing information across routing areas of a computer network. Because the edge-device labels are distributed separately from network routing information, the process of distributing the edge-device labels does not preclude conventional edge-device address summarizations. Illustratively, a novel “label mapping” LSA is employed for distributing the edge-device labels across routing areas. The label-mapping LSA may be embodied as an area-scope OSPF opaque LSA (type 10) or an IS-IS LSP containing TLVs of area scope. Advantageously, the present invention is generally applicable whenever label values are allocated to edge devices in a multi-area computer network and data is “tunneled” through the network from one edge device to another.

Abstract: A method, apparatus and computer program product for performing inter-area summarization for edge-device addressing are presented. A network is established, the network including a first ABR, an ingress Provider Edge (PE) device in communication with the first ABR, a second ABR in communication with the first ABR, and an egress PE in communication with the second ABR. The first ABR and the second ABR are connected via an RFC3107 BGP session, as are the ingress PE and the first ABR as well as the egress PE and second ABR. The method further includes performing packet forwarding including PE address summarization through the network.

Abstract: A system provides a request for a policy from a policy server, and receives the policy from the policy server. The policy indicates processing to be applied to a traffic partition passing through the device. The system configures the policy within a routing structure associated with the traffic partition for the policy in the device, and routes a stream of traffic for the routing structure in accordance with the policy for that routing structure.

Abstract: A novel fast reroute (FRR) technique is provided for quickly and efficiently rerouting selected types of network traffic in response to a node or link failure at the edge of a computer network. According to the technique, the network includes first and second edge devices that function as “FRR mates,” such that network traffic originally destined for one FRR mate may be quickly rerouted to the other without having to wait for conventional network convergence. When an edge device receives rerouted packets originally destined for its FRR mate, the device responds by forwarding only those rerouted packets matching the selected traffic types; rerouted packets that do not match the selected traffic types are dropped or otherwise discarded. The first and second edge devices may be statically configured as FRR mates, e.g., by a network administrator, or they may be configured to automatically detect their compatibility as FRR mates.

Abstract: A method and computer program product for providing autonomous system interconnect for a first peer device is presented. The method includes producing routing information at a first peer. Next, the first peer device provides a context identifier in the routing information. A context authenticator is also provided in the routing information at the first peer. The first peer then advertises this routing information to a second peer. The first peer only accepts messages from the second peer which include the context identifier and the context authenticator.

Abstract: A routing mechanism provides network segmentation preservation by route distribution with segment identification, policy distribution for a given VPN segment, and encapsulation/decapsulation for each segment using an Ethernet VLAN_ID, indicative of the VPN segment (subnetwork). Encapsulated segmentation information in a message packet identifies which routing and forwarding table is employed for the next hop. A common routing instance receives the message packets from the common interface, and indexes a corresponding VRF table from the VLAN ID, or segment identifier, indicative of the subnetwork (e.g. segment). In this manner, the routing instance receives the incoming message packet, decapsulates the VLAN ID in the incoming message packet, and indexes the corresponding VRF and policy ID from the VLAN ID, therefore employing a common routing instance over a common subinterface for a plurality of segments (subnetworks) coupled to a particular forwarding device (e.g. VPN router).

Abstract: A method, apparatus and computer program product for providing convergence for a dual-homed site in a network is presented. An occurrence of a failure between a first Provider Edge (PE) device and a first Customer Edge (CE) device in communication with a dual-homed site is detected. A determination is made whether an alternate route exists for the dual-homed site in a routing table associated with the first PE device. When an alternate route exists then a routing entry associated with the first CE device in a routing table of said first PE device is kept from being deleted for a predetermined amount of time, the routing table is modified to reference the alternate route, the routing entry is rewritten to perform a POP and lookup in a VRF table of the first PE device, and the routing entry is deleted after the predetermined amount of time has elapsed.

Abstract: An MPLS router operable for labeled switch path (LSP) operation defines a compression index for identifying a decompression context between other MPLS LSP routers. The compression index allows a multipoint-to-point link between MPLS routers, thereby avoiding an exhaustive mesh of point-to-point links between each of the MPLS routers. The originator ID identifies each of the multipoint originating endpoints at a common destination, and maintains the context of each compressed header to match incoming compressed headers to the corresponding header values. The originator ID, typically the IP address of the originator, operates as the compression index on the multipoint-to-point connection, operable to distinguish multiple originators of the multipoint-to-point connection and provide header compression for each.

Abstract: A method and computer system for auto-routing of multi-hop pseudowires is presented. A first Provider Edge (PE) device receives an advertisement from a layer 2 (L2) capable network device, the advertisement including routing state for reaching the L2 device. A first Border Gateway Protocol (BGP) table is populated with the routing state for said L2 capable network device which is reachable by way of an address family reserved for L2 end point reachability information. The first PE device advertises the first BGP table information within a first Service Provider (SP) network such that a multi-hop Pseudowire is capable of being established which includes the L2 capable device.

Abstract: In response to a failure within a sub-network of a heterogeneous network, an external device is signaled that the failure has occurred by inclusion of an encoded identifier of the failure location with the signaling. The encoded identifier enables identification of the failure location within the sub-network while masking the identity of the failure location to the external device, and may be realized by using an encrypted sub-object or a token that is associated with the failure location information, which remains stored within the sub-network. The external device responds by issuing a path-establishment message indicating that a new communications path should be established and should exclude the failure location as identified by the encoded identifier, which is included in the path-establishment message.

Abstract: A given router in the core of a label-switching network identifies a group of routers to receive common label binding information for later routing packets along respective paths through the label-switching network. One way to identify which of multiple routers to include as a member of the group to receive the same label information is to analyze egress policies associated with downstream routers in the label-switching network. Based on this analysis, the given router identifies group members as routers having a substantially same egress policy as each other. The given router then allocates memory resources to store a common set of label information to be distributed to each member in the group of routers having the same egress policy. After populating the memory resources with label information, the given router distributes a common set of label information to each router in the group of routers.

Abstract: A path verification protocol (PVP) which enumerates a series of messages sent to a set of nodes, or routers, along a network path identifies connectivity and transmission characteristic attributes by defining, implementing, and analyzing path verification messages (PVMs) in a VPN environment. Typical VPN environments are characterized by service level agreements (SLAs) between service providers which specify particular service level and/or bandwidth level guarantees, typically in terms of megabits per second (MB/s) or other qualitative transfer criteria. Such guarantees are often expressed in contractual terms as Quality of Service (QoS) criteria. Configurations herein provide a mechanism for determination of paths and/or routes that satisfy a QoS or other delivery speed/bandwidth guarantee. Such a mechanism may therefore be employed to perform routing decisions for QoS based traffic.

Abstract: A system and method are provided for separately distributing edge-device labels and routing information across routing areas of a computer network. Because the edge-device labels are distributed separately from network routing information, the process of distributing the edge-device labels does not preclude conventional edge-device address summarizations. Illustratively, a novel “label mapping” LSA is employed for distributing the edge-device labels across routing areas. The label-mapping LSA may be embodied as an area-scope OSPF opaque LSA (type 10) or an IS-IS LSP containing TLVs of area scope. Advantageously, the present invention is generally applicable whenever label values are allocated to edge devices in a multi-area computer network and data is “tunneled” through the network from one edge device to another.