62 results about "Label switching router" patented technology

Detecting if a label-switched path (LSP) is functioning properly. To test that packets that belong to a particular Forwarding Equivalence Class (FEC) actually end their MPLS LSP on an label switching router (LSR) that is an egress for that FEC, a request message carrying information about the FEC whose LSP is being verified may be used. The request message may be forwarded like any other packet belonging to that FEC. A basic connectivity test as well as a fault isolation test are supported. In a basic connectivity test mode, the packet should reach the end of the LSP, at which point it is sent to the control plane of the egress LSR. The LSR then verifies that it is indeed an egress for the FEC. In a fault isolation test mode, the packet is sent to the control plane of each transit LSR, which performs various checks that it is indeed a transit LSR for the LSP. The transit LSR may also return further information that helps check the control plane against the data plane, i.e., that forwarding matches what the routing protocols determined as the path. A reliable return path is used for the reply.

Path determination constraints may be encoded in the form of a program having one or more instructions. Each of instructions may include an operation code, and operands (or pointers to locations where operands are stored). In this way, an extensible, interoperable way for a nodes (e.g., label-switching routers) to communicate constraints within a network is provided. Such constraints may be inserted (e.g., as one or more CONSTRAINT objects) into signaling messages (e.g., a PATH RSVP message). By enabling the signaling of constraints, the determination of constraint-based (label-switched) paths can be distributed among a number of (label-switching) routers or other nodes. Upon receiving a message with constraints (e.g., a CONSTRAINT object(s)), a node may (i) ignore the constraints if the node is a tail-end node (label-switching router), (ii) apply the constraints to a link if the next hop in the (label-switched) path is strict, and / or (iii) perform a constraint-based path determination to a next hop if the next hop is loose.

A technique triggers packing of path computation requests (PCRs) for traffic engineering (TE) label switched paths (LSPs) that are sent from one or more label-switched routers (LSRs) to a path computation element (PCE) of a computer network. According to the novel technique, incoming PCRs are packed into sets in response to a certain event, and one or more TE-LSPs (paths) are computed for each PCR of a particular set based on the PCRs of that set. Specifically, the PCE detects an event in the network (“network event”) indicating that an increase in the number of incoming PCRs has occurred, or that an increase is likely to occur due to, e.g., a change in a network element. Once the network event has been detected, the PCE packs the incoming PCRs into configured-length sets, such as, e.g., for a specified time interval or a certain number of PCRs. The PCE computes paths for each PCR of a particular set while considering the other PCRs of that set, thereby reducing race conditions, signaling overhead, and set-up failures.

A method and system for network topology. The method includes: dividing Label Switching Routers in a single control area into multiple sub-areas, wherein the Label Switching Routers in each sub-area constitute Open Shortest Path First neighbors; obtaining Traffic Engineer resource information on each said sub-area, collecting the Traffic?Engineer resource information on all the sub-areas, and generating a network topology diagram in the single control area.