AT&T Intellectual Property I, LP

At+t Corp.

Bruce Gilbert Cortez

Pravin Kumar Johri

Sanja Durinovic-Johri

Simon S Zelingher

John Paggi

Sid Chaudhuri

Karel Ehrlich

Teddy Bezoza

James H King

Robert Duncan Doverspike

Rakesh Sinha

John Lester Strand

Fang Yu

Martin Birk

Mitchell Harvey Fuchs

Kathleen Tse

Frank Cariello

James Frederick Bradley

Philip Wisseman

Aswatnarayan Raghuram

Paul Greendyk

Ahmet Vecdet Arslan

John Fraterrigo

Cheryl F Newman

Sherry L McCaughan

James Capaldi Jr

Matthew Guardo

David Schmuckler

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

Method and apparatus for initiating routing messages in a communication network

Additional bandwidth is provisioned to layer 2/3 networks by initially provisioning optical wavelength channels to meet incremental needs for additional capacity. When bandwidth requirements grow large enough, a wavelength-sized channel is provisioned to meet the bandwidth needs, and the previously provisioned optical wavelength channels are freed up to be reused for additional growth. The optical wavelength channels may be channelized VLANs mapped to resizable optical channel data units such as ODUflex units.

Layer 1 fast provisioning and right sizing of bandwidth for layer 2/3

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.

Scheme for randomized selection of equal cost links during restoration

A method and a system for allocating restoration capacity in a network link in a communications network provides that a common pool of communication capacity is provisioned in a network link, such that the common pool of communication capacity includes spare capacity for new service and restoration capacity. A pool of pre-allocated communication capacity for future growth of at least one connection in the network link is also provisioned. The pool of pre-allocated communication capacity for future growth is available for restoration capacity, but not for spare capacity for new service. The communications network can be, for example, a private line (PL) network, a SONET-based network, an Asynchronous Transfer Mode (ATM)-based network, an Internet Protocol/MultiProtocol Label Switching (IP/MPLS)-based network or a frame relay (FR)-based network.

A connection in an optical communication system is routed over a sequence of cross-connects and aggregated links comprising multiple links. A different link selection algorithm is used for service provisioning than is used for restoration, i.e., after a cable cut or other failure or incident has made one or paths in the network suddenly unavailable. In particular, a special link selection algorithm called the Interleave algorithm is used for restoration different from the well known Best-Fit algorithm used for provisioning. The Interleave algorithm substantially reduces the probability of glare while maintaining near-optimum capacity utilization.

Link selection schemes for avoiding channel contention

A method is disclosed for replacing legacy interfaces of add drop ring optical networks using STS-3 granularity with an optical hub using STS-1 granularity. In order to avoid locking up ports on the optical hub with dedicated STS-3 packages, a signal broadcast feature of the optical hub, originally provided for remote provisioning, may be adapted to allow a single port to broadcast a signal on multiple and contiguous timeslots to the legacy networks expecting STS-3 granularity.

Method and apparatus for accommodating different switch matrix granularities in optical networks

Growing community of inventors

Marlboro, NJ, United States of America

Bruce Gilbert Cortez