Cisco Technology, Inc.

Cisco Systems Inc.

George Swallow

Clarence Filsfils

Sami Boutros

Muthurajah Sivabalan

David Delano Ward

Thomas David Nadeau

Jean-Philippe Vasseur

Carlos M Pignataro

Stewart Frederick Bryant

James Neil Guichard

Danny Prairie

Ian Michael Charles Shand

Luca Martini

Vanson Lim

Nagendra Kumar Nainar

Stefano Benedetto Previdi

Zafar Ali

Ornan Alexander Gerstel

Nobushige Akiya

Bin Mo

David Ojemann

Yufei Shi

Fred Messinger

Ali Sajassi

Rajiv Asati

Samer Salam

Anna Charny

Tarek Saad

Eric Osborne

John H W Bettink

Reshad Rahman

Carol Etta Iturralde

Monique Jeanne Morrow

Bruce Stuart Davie

Robert Goguen

Daniel C Frost

W Mark Townsley

Richard W Bradford

Ashok Narayanan

Horia Miclea

Nagendra Kumar

Simon James Trevor Spraggs

Show Chung Chin

Simon Spraggs

Neil Jarvis

Nagi Reddy Jonnala

Michael T Piecuch

Azhar Mohammed Sayeed

Matthew Hartley

Jean-Phillipe Vasseur

Noboshige Akiya

In one embodiment, a device in a network determines that traffic sent via a first label switched path should be sent via a new label switched path. The device sends the traffic along the new label switched path using a label stack that indicates one or more adjacency segments or interface binding labels. A particular node along the new label switched path is configured to forward the traffic via a particular interface of the node based on a corresponding interface binding label or adjacency segment indicated by the traffic. The device completes a switchover from the first path to the new path.

Make-before-break mechanism for label switched paths

A method, apparatus, and computer-readable storage medium are disclosed for processing shared risk group (SRG) information in communications networks. The method includes processing, at a domain in a network, first network information comprising a plurality of SRG identifiers. The processing includes producing second network information comprising a smaller number of SRG identifiers than that of the plurality of SRG identifiers. The method further includes sending at least a portion of the second network information to a second domain in the network. The apparatus includes a network interface adapted to send network information comprising SRG information, a processor coupled to the network interface, and a memory coupled to the processor and adapted to store program instructions operable to carry out steps of the method. The storage medium is configured to store program instructions that when executed are configured to cause a processor to carry out steps of the method.

Identifying, translating and filtering shared risk groups in communications networks

Particular embodiments described herein provide for a communication system that can be configured to identify a system that includes network traffic, where at least a portion of the network traffic includes packets, at least a portion of the packets include a stack, and at least a portion of each stack includes one or more previously allocated labels. The communication system can further be configured to determine a synonymous label that triggers an action and to replace a label from the one of the one or more previously allocated labels in a specific stack of a specific packet with the synonymous label. In an example, the synonymous label can be used to identify a subset of packets in the network traffic or a source of the specific packet.

Synonymous labels

In one embodiment, primary circuits may be established on a network link, where each primary circuit individually allocates primary bandwidth of the network link and is assigned to one of either a respective primary weighted queue of the network link corresponding to a size of the respective primary circuit or a shared primary weighted queue of the network link corresponding to a total size of the individually allocated primary bandwidth for the network link. In addition, protection circuits may also be established on the network link, where the protection circuits collectively allocate shared backup bandwidth of the network link and are assigned to a shared backup weighted queue of the network link corresponding to a size of the shared backup bandwidth for the network link. As such, primary and backup packets may be forwarded on the network link according to the primary and backup weighted queues (e.g., allowing 1:1 protection).

Packet transport shared mesh protection

A method, apparatus, and computer-readable storage medium are disclosed for processing shared risk group (SRG) information in communications networks. The method includes processing, at a first network layer, first network information comprising a plurality of SRG identifiers. The processing includes producing second network information comprising a smaller number of SRG identifiers than that of the plurality of SRG identifiers. The method further includes sending at least a portion of the second network information to the second network layer. The apparatus includes a network interface adapted to send network information comprising SRG information, a processor coupled to the network interface, and a memory coupled to the processor and adapted to store program instructions operable when executed to carry out steps of the method. The storage medium is configured to store program instructions that when executed are configured to cause a processor to carry out steps of the method.

The present disclosure provides for carrying downstream mapping information in an echo request message and/or echo reply message, which can describe both IP (Internet Protocol) multipath information and label multipath information. A transit node (e.g., an LSR element) that receives an echo request message from an initiator node determines downstream mapping information, which is returned to the initiator node. Transit node determines whether a newly defined type of multipath information (type 10) should be generated to return the downstream mapping information, based on whether transit node performs load balancing based on labels or IP header information, and whether transit node imposes entropy labels. A multipath information type 10 element includes either IP multipath information or label multipath information, as well as associated label multipath information that includes one or more entropy labels that map to the IP or label multipath information being returned.

LSP ping/trace over MPLS networks using entropy labels

In one embodiment, a method includes generating at a network device, a continuity test packet configured to pass through a set of communication paths terminating at the network device and at least one other network device located at an opposite end of the communication paths, transmitting at the network device the continuity test packet on a first communication path in the set of communication paths, and identifying at the network device a failure in the set of communication paths if the continuity test packet is not received on a last communication path in the set of communication paths. An apparatus and logic are also disclosed herein.

Scalable continuity test for a group of communication paths

In one embodiment, a source transmits one or more data packets to a destination over a primary pseudowire (PW). When a device on the primary PW detects a downstream failure of the primary PW, and in response to receiving one or more data packets from a source from the failed primary PW, the device adds a loopback packet identifier to the one or more received data packets, and returns the one or more data packets with the loopback packet identifier to the source upstream on the primary PW. Accordingly, in response to receiving the data packet returned with a loopback packet identifier from the primary PW (in response to the downstream failure), the source retransmits the one or more data packets to the destination over a backup PW.

Data-plane driven fast protection mechanism for MPLS pseudowire services

In one embodiment, an ingress router sends a multipath information query across a computer network toward an egress router, and builds an entropy table based on received query responses. The entropy table maps the egress router to one or more available paths to the egress router, and associated entropy information for each respective available path of the one or more available paths. The ingress router may then forward traffic to the egress router using the entropy table to load share the traffic across the one or more available paths using the associated entropy information for each respective available path. In response to detecting a failure of a particular path of the one or more available paths, however, the ingress router then removes the particular path from the entropy table, thereby ceasing forwarding of traffic over the particular path.

Reliable multipath forwarding for encapsulation protocols

In one embodiment, a method includes receiving at a node in a first network, information identifying a spare interface between a first network device in the first network and a second network device in a second network, and using the spare interface to create a path in the first network if the spare interface is compatible. The spare interface information includes connectivity and compatibility information.

Discovery of connectivity and compatibility in a communication network

In an embodiment, a method comprises: receiving a data communications packet comprising one or more labels in a label stack; determining whether a table identifier is present in the label stack. In response to determining that the table identifier is present in the label stack: based, at least in part, on the table identifier, a label table is determined; a next hop for the data communications packet is determined by performing a next-hop lookup in the label table using at least one of the one or more labels; and the data communications packet is forwarded to the next hop. In an embodiment, the method is performed by one or more computing devices.

Universal labels in internetworking

In one embodiment, a circuit that extends between a head-end label switching router (LSR) and a tail-end LSR and traverses one or more intermediate LSRs is locked to data plane traffic. The head-end LSR transmits a packet along the circuit that includes a particular time-to-live (TTL) value configured to expire at a particular intermediate LSR at which loopback is to occur. The circuit is used in a loopback mode. The head-end LSR transmits along the circuit a packet that includes a cease loopback request. The circuit ceases to be used in the loopback mode. The circuit is unlocked to permit the circuit to pass data plane traffic.

Operating MPLS label switched paths and MPLS pseudowire in loopback mode

A technique may improve LDP-IGP synchronization in a MPLS network when an interface of a router coupled to a communications link along a shortest path between a source router and a destination router becomes newly active. Specifically, an IGP adjacency may be held down over the newly active link while a LDP adjacency is established over the link. The router may inject a temporary, non-redistributable route having a large administrative weight into its routing table utilizing addresses learned during establishment of the LDP adjacency. The injected route ensures that there is a reachable route to a peer router so that LDP may converge. After LDP has converged and all needed label bindings have been distributed in the MPLS network utilizing the injected route, IGP executing on the router may advertise a normal cost metric for the link associated with the newly active interface, and IGP convergence may be completed.

Technique for improving LDP-IGP synchronization

In one embodiment, a replacement network communications path is determined using dedicated resources of an existing path. One or more network elements in a network determines a new communications path between a first network node and a second network node in the network while an existing communications path is currently configured in the network to carry traffic between the first and second network nodes. The existing communications path includes one or more exclusive physical resources dedicated to the existing communications path. The new communications path includes at least one of said exclusive physical resources dedicated to the existing communications path. One embodiment includes: subsequent to said determining the new communications path, removing the existing communications path from service, and then instantiating the new communications path, with the new communications path including said at least one of said exclusive physical resources.

Replacing an existing network communications path with a new path using some exclusive physical resources of the existing path

A method, apparatus, and computer-readable storage medium are disclosed for processing shared risk group (SRG) information in communications networks. The method includes obtaining at least one SRG identifier by processing SRG information included in network information received at a first network layer from a second network layer, and processing the at least one SRG identifier using one or more operations configured to ensure that the SRG identifier is unique among a plurality of SRG identifiers. The apparatus includes a network interface adapted to receive network information comprising SRG information, a processor coupled to the network interface, and a memory coupled to the processor and adapted to obtain at least one SRG identifier by processing the SRG information and to process the at least one SRG identifier. The computer-readable storage medium is configured to store program instructions that when executed are configured to cause a processor to perform the method.

Growing community of inventors

Boston, MA, United States of America

George Swallow