Abstract: Systems and methods of network traffic engineering are provided. The system includes a switch and a controller. The controller can maintain a monitoring segment identifier set defining a path for traffic intended for a destination device. The controller can maintain a forwarding segment identifier set representing a compressed version of the monitoring segment identifier set such that traffic, when labeled according to the forwarding segment identifier set, will follow the path defined by the monitoring segment identifier set. The controller can monitor a status of the path defined by the monitoring segment identifier set. The controller can, subject to determining that the path defined by the monitoring segment identifier set is invalid, cause the switch to not label a packet received at the switch according to the forwarding segment identifier set.

Abstract: Systems and methods of network traffic engineering are provided. The system includes a switch and a controller. The controller can maintain a monitoring segment identifier set defining a path for traffic intended for a destination device. The controller can maintain a forwarding segment identifier set representing a compressed version of the monitoring segment identifier set such that traffic, when labeled according to the forwarding segment identifier set, will follow the path defined by the monitoring segment identifier set. The controller can monitor a status of the path defined by the monitoring segment identifier set. The controller can, subject to determining that the path defined by the monitoring segment identifier set is invalid, cause the switch to not label a packet received at the switch according to the forwarding segment identifier set.

Abstract: In general, techniques are described for automated traffic mapping for multi-protocol label switching (MPLS) networks. A network device comprising a processor and an interface card may perform the techniques. The processor may generate an advertisement that conforms to a routing protocol. The advertisement may advertise a mapping between a network flow and a label switched path (LSP) tag. The processor may also generate a communication associating the label switched path tag with an LSP. The interface card may transmit the advertisement to a head-end label edge router that admits traffic into the LSP identified by the LSP tag. The interface card may also transmit the communication to the label edge router such that the label edge router is able to process the communication in conjunction with the advertisement to map the network flow to the LSP identified by the LSP tag.

Abstract: A system and method for handling critical events in service delivery gateways. Events are defined that cause a transition from a master redundancy state to a standby redundancy state in service delivery gateways and a plurality of signal-routes are stored. Each signal-route is associated with one or more of the defined events. A first defined event is detected in the first service delivery gateway and causes a transition from the first master redundancy state to the first standby redundancy state in the first service delivery gateway and a change in a first signal-route from the plurality of signal-routes in the first service delivery gateway. The change in the first signal-route is advertised and a second service delivery gateway transitions from the first standby redundancy state to the first master redundancy state.

Abstract: An access network is described in which a centralized controller provides seamless end-to-end service from a core-facing edge of a service provider network through aggregation and access infrastructure out to access nodes located proximate the subscriber devices. The controller operates to provide a central configuration point for configuring aggregation nodes (AGs) of a network of the service provider so as to provide transport services to transport traffic between access nodes (AXs) and edge routers on opposite borders of the network.

Abstract: Techniques of this disclosure enable loop protection for networks that utilize hop-by-hop routing, such as networks that utilize multi-protocol label switching (MPLS) label distribution and interior gateway protocol (IGP) routing. As described herein, the techniques provide protection from any small transient loops that may emerge due to link failure or other topology change events in networks that utilize hop-by-hop routing techniques.

Abstract: In one example, a method includes establishing a plurality of label switched paths (LSPs) having a common transit network device other than an ingress network device or an egress network device of any of the plurality of LSPs, and, by the transit network device along the plurality of LSPs, detecting a congestion condition on a link along the plurality of LSPs and coupled to the transit network device. The method also includes, responsive to detecting the congestion condition, and by the transit network device, selecting a subset of the plurality of LSPs to evict from the link, wherein the subset comprises less than all of the plurality of LSPs, and updating a forwarding plane of the transit network device to reroute network traffic received for the selected subset of the plurality of the LSPs for forwarding to a next hop on a bypass LSP that avoids the link.

Abstract: In general, techniques are described for automated traffic mapping for multi-protocol label switching (MPLS) networks. A network device comprising a processor and an interface card may perform the techniques. The processor may generate an advertisement that conforms to a routing protocol. The advertisement may advertise a mapping between a network flow and a label switched path (LSP) tag. The processor may also generate a communication associating the label switched path tag with an LSP. The interface card may transmit the advertisement to a head-end label edge router that admits traffic into the LSP identified by the LSP tag. The interface card may also transmit the communication to the label edge router such that the label edge router is able to process the communication in conjunction with the advertisement to map the network flow to the LSP identified by the LSP tag.

Abstract: Techniques are described for establishing a point-to-multipoint (P2MP) label switched path (LSP) using a branch node-initiated signaling model in which branch node to leaf (B2L) sub-LSPs are signaled and utilized to form a P2MP LSP. The techniques described herein provides a scalable solution in which the number of sub-LSPs for which the source node or any given branch node need maintain state is equal to the number of physical data flows output from that node to downstream nodes, i.e., the number of output interfaces used for the P2MP LSP by that node to output data flows to downstream nodes. As such, unlike the conventional source node-initiated model in which each node maintains state for sub-LSPs that service each of the leaf nodes downstream from the device, the size and scalability of a P2MP LSP is no longer bound to the number of leaves that are downstream from that node.

Abstract: An access network is described in which a centralized controller provides seamless end-to-end service from a core-facing edge of a service provider network through aggregation and access infrastructure out to access nodes located proximate the subscriber devices. The controller operates to provide a central configuration point for configuring aggregation nodes (AGs) of a network of the service provider so as to provide transport services to transport traffic between access nodes (AXs) and edge routers on opposite borders of the network.

Abstract: An access network is described in which a centralized controller provides seamless end-to-end service from a core-facing edge of a service provider network through aggregation and access infrastructure out to access nodes located proximate to the subscriber devices. The controller operates to provide a central configuration point for configuring aggregation nodes (AGs) of a network of the service provider so as to provide transport services to transport traffic between access nodes (AXs) and edge routers on opposite borders of the network.

Abstract: An access network is described in which a centralized controller provides seamless end-to-end service from a core-facing edge of a service provider network through aggregation and access infrastructure out to access nodes located proximate to the subscriber devices. The controller operates to provide a central configuration point for configuring aggregation nodes (AGs) of a network of the service provider so as to provide transport services to transport traffic between access nodes (AXs) and edge routers on opposite borders of the network.

Abstract: Filters are selectively applied to packets depending on forwarding equivalence classes (FECs) of the packets. A FEC filter is defined within the network device and qualified by incoming interface information that identifies source sites of the packets. A label distribution protocol (LDP) FEC is configured such that packets of the given FEC are associated with the FEC filter. The FEC identifies a destination site of the packets received by the router and is automatically combined with incoming interface information. In this way, packet flows may be filtered based on FECs of the packets. FEC filters may be further refined to operate at forwarding class granularity. The techniques allow accurate billing of packets traveling between specific source and destination sites regardless of the number of interfaces of the network device the packets utilize. In addition, the filtering can be used to provide anti-spoofing capabilities.

Abstract: A router receives a control plane message for constructing a first LSP to a destination within a network that conforms to a first type of LSP. The control plane message includes a label for the first LSP and an identifier that identifies a first type of data traffic. The router receives a second control plane message for constructing a second LSP that conforms to the first type of LSP. The second control plane message includes a label for the second LSP and an identifier that identifies a second type of data traffic. The router installs forwarding state in accordance with policies that associate the first and second types of data traffic with different LSPs of a second type that each traverse different paths through the network, and forwards packets via the interface in accordance with the installed forwarding state.

Abstract: Constraint information associated with peering links is taken into account when establishing label switched paths (LSPs) to exit points of a network. Devices within the network, such as routers, designate interfaces associated with peering links as “passive interfaces” to indicate that the interfaces should be included for bandwidth accounting purposes and internal path computation. Other devices within the network utilize the constraint information, e.g., bandwidth availability, when computing and establishing LSPs to the exit points of the network to avoid congested peering links.

Abstract: Label distribution protocol (LDP) signaled label-switched paths (LSPs) are supported without requiring information about remote autonomous systems (ASs) to be injected into the local interior gateway protocol (IGP). This may be done by (i) decoupling a forwarding equivalency class (FEC) element from the routing information, and (ii) specifying a next hop on which the FEC relies. An LDP messaging structure (e.g., an LDP type-length-value (TLV)) that includes a label, FEC information (e.g., a host address or prefix of an egress LSR of the LSP) and a next hop (e.g., a host address or prefix of a border node, such as an AS border router (ASBR)) may be provided. This messaging structure may be included in one or more of (a) label mapping messages, (b) label withdraw messages, and (c) label release messages.

Abstract: A router comprises an interface for receiving packets, wherein the packets include Multiprotocol Label Switching (MPLS) labels having the same label value that corresponds to an MPLS label switched path (LSP), and wherein each of the MPLS packets includes MPLS experimental (EXP) bits defined to identify a class of service to which the respective packet belongs. The router is a transit router along the MPLS LSP, and further includes a control unit that, for each of the packets, accesses forwarding information to determine whether to forward the packet along the LSP or to redirect the packet along a second LSP based on the classes of service specified in the EXP bits. The router receives policies via a user interface, and applies the policies to index into the forwarding information to select a forwarding entry, wherein the index is responsive to the label value in combination with the EXP bits.

Abstract: The label distribution protocol (LDP) is extended to set up a point to multi-point (P2MP) label switched path (LSP) across a computer network from a source network device to one or more destination network devices. LDP is extended to create a P2MP label map message containing a label and a P2MP forwarding equivalence class (FEC) element having a root node address and an identifier. The P2MP FEC element may, for example, associate an address of the root node of the P2MP LSP with an opaque identifier. The P2MP FEC element uniquely identifies the P2MP LSP. The P2MP FEC element may be advertised with a label in a P2MP label map message. A source network device or the destination network devices may initiate setup and teardown of the P2MP LSP. The P2MP label map messages may be propagated from the destination network devices to the source network device.

Abstract: Filters are selectively applied to packets depending on forwarding equivalence classes (FECs) of the packets. A FEC filter is defined within the network device and qualified by incoming interface information that identifies source sites of the packets. A label distribution protocol (LDP) FEC is configured such that packets of the given FEC are associated with the FEC filter. The FEC identifies a destination site of the packets received by the router and is automatically combined with incoming interface information. In this way, packet flows may be filtered based on FECs of the packets. FEC filters may be further refined to operate at forwarding class granularity. The techniques allow accurate billing of packets traveling between specific source and destination sites regardless of the number of interfaces of the network device the packets utilize. In addition, the filtering can be used to provide anti-spoofing capabilities.

Abstract: A system distributes extended traffic accounting information of bandwidth availability on links throughout a network. For example, routers within the network utilize an extended reservation protocol to calculate bandwidth availability information for links. In calculating the bandwidth availability information, the extended reservation protocol accounts for not only the amount of bandwidth reserved on each of links via the resource reservation protocol itself, but also for the bandwidth usage by other traffic on the links, such as Label Distribution Protocol (LDP) traffic or Internet Protocol (IP) traffic. The routers exchange bandwidth availability information using a routing protocol to gain network-wide knowledge of bandwidth availability.