At&t Intellectual Property I, L.p.

At+t Corp.

Lucent Technologies Inc.

At&t Bell Laboratories

Pravin Kumar Johri

Sanja Durinovic-Johri

Bruce Gilbert Cortez

Simon S Zelingher

John Paggi

Huajin Jeng

Samir S Saad

Cagatay Buyukkoc

Han Q Nguyen

Kathleen S Meier-Hellstern

David James Houck, Jr

Rodolfo Alberto Milito

Bharat Tarachand Doshi

Karel Ehrlich

Teddy Bezoza

Steven M Michelson

Steven S Katz

Arik Kashper

Thomas S Giuffrida

James H King

Mahalakshmi Jairam

Arun N Netravali

Krishan Kumar Sabnani

Subrahmanyam Dravida

Danielle Liu

Paramasiviah Harshavardhana

Christopher Flores

Norman Farber

Adrian Emmanuel Eckberg

Patamasiviah Harshavardhana

Sanj Durinovic-Johri

Notman Farber

Methods, apparatus, and articles of manufacture to provide a multicast virtual private network (MVPN) are disclosed. Example methods to transmit multicast data in a network disclosed herein include monitoring, with a first network node, a multicast data flow to determine a characteristic for triggering a switch from a first logical topology for the multicast data flow to a second logical topology for the multicast data flow. Disclosed example methods also include, after the switch to the second logical topology, accessing a multicast data packet associated with a first multicast route generated for the multicast data flow from a second network node, and transmitting a first replication of the multicast data packet to a third network node via a unicast path, the first replication of the multicast data packet to include a first label provided by the third network node to identify the first multicast route.

Methods, apparatus, and articles of manufacture to provide a multicast virtual private network (MVPN)

Switches within a telecommunications network exchange so-called available bandwidth messages, each of which advertises how much bandwidth remains unassigned on a respective link. The network is of a type in which circuits are provisioned with various predefined numbers of time slots (equivalent to bandwidth). The sending of an available bandwidth message for a given link is triggered by a change in the number of time slots available on that link if that change results in a change in the number of circuit bandwidths that can be accommodated by that link for a newly provisioned circuit.

Advertising messages in networks

Methods, apparatus, and articles of manufacture to provide a multicast virtual private network (MVPN) are disclosed. An example method to transmit multicast data over a communication network includes receiving, at a first machine, a multicast data packet from an ingress provider edge router of the communication network, the multicast data packet associated with a multicast route, and transmitting a first replication of the multicast data packet from the first machine to a second machine via a first unicast path. The first replication of the multicast data packet includes a first label provided by the second machine to identify the multicast route in the second machine. Example methods further include receiving the first replication of the multicast data packet at the second machine via the first unicast path, and replicating the multicast data packet from the second machine to an egress provider edge router of the communication network.

Method and apparatus for initiating routing messages in a communication network

Example methods disclosed herein include registering a first leaf node to receive multicast data from a source via a first network node in response to receiving, from the first leaf node, a first message addressed to an anycast address, the anycast addressed being assigned to the first network node to associate the first network node with a second hierarchical level of a replication hierarchy. The disclosed example methods also include receiving the multicast data from a second network node associated with a first hierarchical level of the replication hierarchy. The disclosed example methods further include, after registering the first leaf node with the first network node, replicating the multicast data to generate copies of the multicast data to be transmitted via respective unicast paths to respective ones of a plurality of leaf nodes, including the first leaf node, registered with the first network node to receive the multicast data.

Methods and apparatus for network multicasting using hierarchical replication

Methods, apparatus, and articles of manufacture to provide a multicast virtual private network (MVPN) are disclosed. An example method to transmit multicast data over a communication network includes: determining an upstream hop of a multicast transmission based on a received hierarchical ingress replication route; storing a downstream hop and the upstream hop of the multicast transmission in a multicast routing table; monitoring the multicast transmission occurring via an area border router; in response to detecting at least one of a) a threshold fan-out of the multicast transmission or b) a threshold data rate from a source of the multicast transmission, converting a logical topology of the multicast transmission; and in response to receiving a multicast data packet of the multicast transmission, replicating the multicast data packet with the processor based on the downstream hop.

Methods, apparatus, and articles of manufacture to provide a multicast virtual private network (MVPN) are disclosed. An example method includes sending a multicast receiver route received from one of a multicast service processor or a provider edge router to another of the multicast service processor or the provider edge router, wherein the multicast service processor is communicatively coupled to the provider edge router via a multicast control plane topology that is non-congruent to a unicast control plane topology, and replicating multicast data received from the other of the multicast service processor or the provider edge router to the one of the provider edge router or the multicast service processor based on the multicast receiver route.

Methods and apparatus for network multicasting using hierarchical replication are disclosed. An example method disclosed herein to send multicast data associated with a source to a plurality of receivers in a network comprises replicating the multicast data received at a first network node, the multicast data received via a first unicast path, the first network node being associated with a first hierarchical level of a replication hierarchy, sending copies of the multicast data to a plurality of network nodes associated with a second hierarchical level of the replication hierarchy via second unicast paths, and replicating a copy of the multicast data received via one of the second unicast paths at a second network node to send the multicast data via a third unicast path for receipt by a receiver in the plurality of receivers, the second network node being in the plurality of network nodes associated with the second hierarchical level.

A data network wherein network links have an assigned service weight and a restoration weight that are used as factors for respectively determining an optimum primary data path and a back-up data path through the network. The restoration path is used in the event of a failure of the primary service path and a Dijkstra or similar algorithm may be used for determining these paths. Service weights may be assigned to the links to prioritize finding the shortest possible path, whereas restoration weights may be assigned to the links to find a path with the maximum available capacity.

Method and apparatus for providing alternative link weights for failed network paths

A system and method is disclosed that assures component circuits transported in aggregated circuits restore correctly after an aggregated circuit fault. The system and method implements component circuit tail segment integrity checks whenever an aggregated circuit is restored in a higher level of a network hierarchy. Switches at both ends of an aggregated circuit perform circuit integrity checks of the tail segments of every component circuit. A failure of the component circuit integrity check on any component circuit causes that component circuit to be released and restored end-to-end.

Restoring aggregated circuits with circuit integrity checks in a hierarchical network

A method and system for provisioning circuits on multiple parallel links with a single setup message is disclosed. A setup message specifying links in a circuit path is transmitted to switches along the circuit path. If a switch determines that a link specified in the setup message has insufficient bandwidth for the circuit, the switch substitutes a parallel link having sufficient bandwidth for the specified link in the circuit path. The setup message can indicate whether substitution for a link is permitted. This can be used to prevent substitution for links when provisioning service routes for new circuits in order to maintain diversity requirements, while allowing substitution for links when provisioning restoration routes for failed circuits in order to reduce restoration time.

Method for provisioning circuits on multiple parallel links with a single setup message

Disclosed example operations involve provisioning a pool of communication capacity in a network link, the pool of communication capacity including spare capacity; allocating from the spare capacity a reserve service communication capacity requested in a connection setup message associated with a first user, the reserve service communication capacity being available to accommodate an increase of communications associated with a first service connection for the first user; and while the reserve service communication capacity is allocated for the first service connection for the first user, provisioning the reserve service communication capacity to be available for restoration capacity associated with a second service connection for at least a second user.

Shared bandwidth reservation in PL, ATM, FR and IP/MPLS networks

The present invention relates generally to restoration of services in a network. More particularly, the invention encompasses a scheme for randomized selection of equal cost links during restoration in a communication network. The invention further includes multiple schemes for restoring services. The network could consist of optical, ATM, FR, or IP/MPLS switches and cross-connects.

Growing community of inventors

Aberdeen, NJ, United States of America

Pravin Kumar Johri