Embodiments relate generally to systems and methods for transitioning a system from a tradition network to a Software Defined Network (SDN) enabled network. In some embodiments, the systems and methods may comprise the use of a Path Computation Element (PCE) as a central controller. Smooth transition between traditional network and the new SDN enabled network, especially from a cost impact assessment perspective, may be accomplished using the existing PCE components from the current network to function as the central controller of the SDN network is one choice, which not only achieves the goal of having a centralized controller to provide the functionalities needed for the central controller, but also leverages the existing PCE network components.

A first network device adapted for communication with one or more other network devices is configured to originate a first route identifying a tunnel for carrying traffic for a multicast, to originate a second route specifying a leaf information requirement for the multicast but not identifying a tunnel for carrying traffic for the multicast, and to track a plurality of receivers of the multicast based at least in part on leaf information received from the multicast receivers responsive to the specified leaf information requirement of the second route. The first route may comprise an inclusive route having a tunnel attribute that identifies an inclusive tunnel for the multicast and the second route may comprise a selective route having a tunnel attribute configured to indicate that it carries no tunnel information. Multicast traffic can be switched between an inclusive tunnel and a selective tunnel responsive to the multicast receiver tracking.

A method of mobility management in a label-switched network comprising a primary domain comprising N label-switched nodes, with N>1, and a mobile domain comprising M mobile label-switched nodes, with M≧1, the mobile domain being movable with respect to said primary domain, packets routing between the primary domain and the mobile domain being performed by means of a primary border node, selected from the N label-switched nodes, and a mobile border node, selected from the M mobile label-switched nodes, wherein a handoff procedure is executed that establishes a label switched connection between the primary border node and the mobile border node.

Embodiments of the present invention provide a Multiprotocol Label Switching traffic engineering tunnel establishing method and device. A tunnel establishing method includes: receiving, by a second routing device, an identifier, which is sent by a first routing device, of an MPLS TE tunnel from a first VPN instance to a second VPN instance; acquiring, by the second routing device according to the identifier, path information of the MPLS TE tunnel from the first VPN instance to the second VPN instance; and establishing an MPLS TE tunnel from the second VPN instance to the first VPN instance according to the acquired path information. Therefore, forward and reverse bidirectional tunnels are co-routed or partially co-routed, thereby solving a problem caused by non-co-routing during BFD.

A receiving node receives a virtual LDP initialization (vInit) message from a first node, where the vInit message comprises a request to establish a vLDP session between a requesting node and a target node. If the receiving node does not own a destination address of the vInit message, the receiving node is determined to be a relay node. The relay node inserts a relay label into the vInit message, where the relay label is an outgoing label that the relay node uses to reach the first node, and forwards the vInit message toward the destination address. If the receiving node owns the destination address, the receiving node is determined to be the target node, which extracts a stack of relay labels from the vInit message. The relay labels are used to define a return path to the requesting node for messages transmitted over the vLDP session.

A label switched path (LSP) establishing method that includes receiving a first path message from a network node outside of a topology-transparent zone (TTZ) along a path for the LSP, computing a TTZ path through the TTZ from the network component to an egress TTZ edge node along the LSP, sending a second path message to a TTZ internal node along the TTZ path, receiving a first reservation (RESV) message from the TTZ internal node that includes a label allocated for the egress TTZ edge node, and sending a second RESV message that includes a label allocated for the network component and the label allocated for the egress TTZ edge node to the network node.

In one embodiment, a traffic engineering (TE) label switched path (LSP) is established between a head-end node in a local domain and a tail-end node in a remote domain. The TE-LSP spans one or more intervening domains located between the local domain and the remote domain. The head-end node sends a routing information request over the TE-LSP to a target node on the TE-LSP that is in the remote domain. The head end node receives routing information from the target node. The received routing information includes a list of address prefixes reachable by the target node. The head end node uses the received routing information to calculate routes reachable via the TE-LSP to the target node. The calculated routes have a next-hop interface set to be the TE-LSP. The calculated routes are inserted into a routing table of the head-end node.

Disclosed are a method and a device for establishing a multi-domain and dual-home path, herein the method includes: a client network sending information of a first dual-home path and a computation request of a dual-home separating path of the first dual-home path to a parent PCE of a serving network with which the client network is associated; the client network receiving information of the dual-home separating path responded by the parent PCE, herein the information of the dual-home separating path is computed by the parent PCE at least according to the information of the first dual-home path; and the client network establishing a second dual-home path according to the information of the dual-home separating path.

One embodiment provides a system that facilitates querying of historical network information. During operation, the system generates a query for historical information associated with interest and content object packets, wherein a name for an interest is a hierarchically structured variable length identifier that includes contiguous name components ordered from a most general level to a most specific level, wherein the query is based on a name prefix that includes one or more contiguous name components. The system transmits the query to a responding entity. In response to receiving the historical information from the responding entity, the system performs an operation that increases network efficiency based on the historical information, thereby facilitating a protocol for querying the historical information to increase network efficiency.

This application discloses a fault protection method, including: A first node determines that a first cross-domain node is faulty. The first node is a head node of a segment routing best effort SR-BE service tunnel, the SR-BE tunnel is a cross-domain tunnel that passes through a first IGP domain and a second IGP domain, the SR-BE tunnel passes through the first cross-domain node, and the first cross-domain node is a node that crosses the first IGP domain and the second IGP domain. The first node switches a service transmission path from the SR-BE tunnel to a backup tunnel. The backup tunnel does not pass through the first cross-domain node, and the backup tunnel is a tunnel with a strict explicit path.