Juniper Networks, Inc.

Lucent Technologies Inc.

Ping Pan

Nischal Sheth

Manoj Leelanivas

Kireeti Kompella

Der-Hwa Gan

Yakov Rekhter

Keith Eric Holleman

Arun Vaidyanathan

James Michael Murphy

Henning Gunther Schulzrinne

Ellen L Hahne

When a node has to restart its control component, or a (e.g., label-switched path signaling) part of its control component, if that node can preserve its forwarding information across the restart, the effects of such restarts on label switched path(s) include the restarting node are minimized. A node's ability to preserve forwarding information across a control component (part) restart is advertised. In the event of a restart, stale forwarding information can be used for a limited time before. The restarting node can use its forwarding information, as well as received label-path advertisements, to determine which of its labels should be associated with the path, for advertisement to its peers.

Graceful restart for use in nodes employing label switched path signaling protocols

A connection between network nodes in a communication network is backed up. A failover switched path such as a label-switched path (LSP) is created starting at a first network node of a connection and ending at the second node of the connection, while bypassing the protected connection. In the event of connection failure, data is transmitted through the failover switched path (e.g., LSP). A network operator can selectively protect different types of data by using filters that bind one or more types of traffic received over one or more interfaces to different failover switched paths (LSPs).

Protecting connection traffic using filters

A connection between network nodes in a communication network is backed up. A failover label-switched path (LSP) is created starting at a first network node of a connection and endingat the second node of the connection, while bypassing the protected connection. In the event of connection failure, data is transmitted through the failover LSP. A network operator can selectively protect different types of data by using filters that bind one or more types of traffic received over one or more interfaces to different failover LSPs.

When a node has to restart its control component, or a (e.g., label-switched path signaling) part of its control component, if that node can preserve its forwarding information across the restart, the effects of such restarts on label switched path(s) the include the restarting node are minimized. A node's ability to preserve forwarding information across a control component (part) restart is advertised. In the event of a restart, stale forwarding information can be used for an limited time before. The restarting node can use its forwarding information, as well as received label-path advertisements, to determine which of its labels should be associated with the path, for advertisement to its peers.

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.

Detecting data plane liveliness of a label-switched path

Outages in a label-switched path (LSP) are detected quickly using adjacency information, such as IGP 'hello neighbor' queries. Protocols, such as IGP can be instructed to check certain adjacencies more frequently. For example, a node in an LSP can determine a next downstream node in the LSP as an adjacency, check that adjacency much more frequently, and in the event that the adjacency is lost (due to a down link, a down interface, or a down node), switch any LSPs that have the adjacency to a failover path or route. Since these checks need not be performed using hardware signaling, outages of shared media interfaces, such as Ethernet and Gigabit Ethernet, can be checked.

Detecting a label-switched path outage using adjacency information

A connection between network nodes in a communication network is backed up. A failover label-switched path (LSP) is created starting at a first network node of a connection and ending at the second node of the connection, while bypassing the protected connection. In the event of connection failure, data is transmitted through the failover LSP. A network operator can selectively protect different types of data by using filters that bind one or more types of traffic received over one or more interfaces to different failover LSPs.

Techniques are described for supporting end-to-end resource reservation protocols, such as the Resource Reservation Setup Protocol (RSVP), using Multi-protocol Label Switching (MPLS). A routing device, such as an edge router coupling a local network to another network, aggregates packet flow reservation requests, and maps the resource requests to Labeled Switch Paths (LSPs) capable of supporting the requested resources. Requests having common forwarding equivalence classes may be aggregated to flow through a single LSP having resources, such as bandwidth, capable of supporting the requests. Routers and other devices within the network need not monitor and support state information associated with the individual end-to-end packet flows. A method, for example, includes mapping requests for end-to-end packet flows through a network to LSPs within the network, and forwarding packets associated with the end-to-end packet flows along the LSPs based on the mapping.

Aggregating end-to-end QoS signaled packet flows through label switched paths

Testing the liveliness of a data plane of a label switched path (LSP) using a two stage approach. The first stage may use a general echo request operation that may be implemented using hardware. Therefore, the first stage does not heavily burden the control plane of the LSR. If a suspect LSP passes the first stage of the diagnostic operation, nothing more needs to be done. If, however, the suspect LSP fails the first stage, the diagnostic operation proceeds to a second stage. The second stage of the diagnostic operation sends probing massages through the suspect LSP, but uses the control plane to deliver the acknowledging messages. If the suspect LSP fails the second stage of the diagnostic operation, the ingress LSR can infer that the LSP is down, and begin recovery actions. The probing messages may include padding so that MTU limits can be tested. In addition, the probing messages may be encapsulated in a protocol that allows flow control, thereby protecting an LSR that can receive such messages from DoS attacks.

Detecting data plane livelines in connections such as label-switched paths

A reservation is created within a network by sending a stateless probe from a source node toward a destination node. The stateless probe determines a reservation path between the source node and the destination node via intermediate routers in the network. A determination is made if the destination node agrees to create the reservation path to the source node. If the destination node agrees to create the reservation path to the source node, the reservation path is established by returning a corresponding response message to the source node. Links included in more than one established reservation path to the same destination node are identified. The multiple reservations on such links are aggregated. This aggregation creates a tree of reservations rooted at the destination node.

Growing community of inventors

Emerson, NJ, United States of America

Ping Pan