Nortel Networks Corporation

Northern Telecom Limited

Ciena Corporation

Ericsson Ab

Rockstar Consortium US LP

David John Stacey

Simon Daniel Brueckheimer

Roy Harold Mauger

Martin Sproat

Mark Robert Gibson

Michael Thomas

Julian Frank Barry Cable

Fai Tsang

Stephen Rylant Evans

Andrew Geoffrey Tomlins

John Andrew Shotton

Leslie Derek Humphrey

Keith Caves

Bruce Leigh Townsend

Stephen Leonard Fagg

Simon Daniel Breuckheimer

Greg M Bernstein

Khaled Maamoun

Benoît Châtelain

Paul Douglas Welton

William Smith

Eric Fai Tsang

Graham Fellows

Osama Bhagat

John Shotton

Partial optimization systems and methods of wavelengths or spectrum in an optical network include, based on current services in the optical network each having a route and wavelength assignment and based on a ratio of services that can be changed in the partial optimization, preforming a first stage optimization to determine which of the current services are changed for one or more of the route and the wavelength assignment to attain a reduction of a number of wavelengths; performing a second stage optimization to determine an order of implementing changes from the first stage optimization that with the order minimizing one or more of conflicts and step counts; and causing implementation of the changes in the optical network.

Optimal partial reconfiguration of spectrum in optical networks

A telecommunications system comprises an asynchronous transfer mode (ATM) network having uncommitted bandwidth, and a plurality of adaptive grooming routers (AGR) coupled to the network. The AGRs comprise a group adapted to function as a virtual transit exchange whose fabric and control are distributed over the group. The visual comprising the AGRs incorporates independent connection control and call routing functions and has means for determining the current system status whereby to set up narrow band connections across the ATM network based on that status determination.

ATM telecommunications systems and method for routing narrow band traffic

Traffic from a number of different service type users is multiplexed into minicells for transmission over an ATM link. Service type information is transmitted in a service specific field and is stored. This stored information is used to derive length information to delineate the different length user minicells. The technique occupies less bandwidth than the conventional methods for transmitting cell length information.

ATM communications system and method

An improved architecture in a circuit switched communications network is provided in which a plurality of network service provider devices, eg intelligent peripherals are arranged to provide network service data to a plurality of time division multiplex circuits and trunks by converting these circuits and trunks to streams of packets, and providing network service data packetized in a set of network service data packet streams to the circuit packet streams without incurring delays to the circuit packet streams. The circuit packet streams may be duplicated and forwarded to the network service provider devices without incurring delay to the ongoing through put packetized circuits, and similarly packet streams containing network service data may be superimposed into the circuit packet streams, without the requirement for the circuit packet streams to be switched to the network service provider devices. The architecture comprises a plurality of TDM interfaces, a plurality of conversion means for converting from time division multiplexed mode to a plurality of packet streams; a plurality of packet streams switching devices and a plurality of network service provider devices.

Network service provider architecture in communications network

On receipt of a request for a communication session over a communications network, such as an Internet Protocol communications network, a path for the session is established. In a preferred example the communications network is an MPLS network and the method uses a modified version of the SIP messaging protocol. Bandwidth along a chosen path is reserved and a messaging protocol such as CR-LDP used to establish this reserved path for the communication session. This creates a delay in the time taken to establish a communication session because the process of choosing a path and reserving bandwidth must be completed before the CR-LDP protocol is used. This delay is reduced by using modified SIP Protocol to perform the CR-LDP function too.

Establishing connections across a communications network

A telecommunications system comprises an asynchronous transfer mode (ATM) network having uncommitted bandwidth, and a plurality of adaptive grooming routers (AGR) coupled to the network. The AGRs comprise a group adapted to function as a virtual transit exchange whose fabric and control are distributed over the group. The virtual comprising the AGRs incorporates independent connection control and call routing functions and has means for determining the current system status whereby to set up narrow band connections across the ATM network based on that status determination.

Point to point protocol (PPP) traffic is transported over an asynchronous transport link by encapsulating the traffic in AAL2 minicells and transporting the minicells in a single virtual circuit. Minicells from a number of users can be multiplexed in the same virtual circuit.

Transporting multiprotocol datagrams

A method of adapting synchronous time division multiplexed (TDM) traffic at an interface between a synchronous network in which the traffic is transported in frames identified by corresponding pointers and labels and an asynchronous network in which the adapted traffic is transported in cells, the method comprising mapping said synchronous frames into primary multiplexed groups, mapping each said primary multiplexed group into traffic cells in a respective asynchronous virtual channel, and providing that virtual circuit with a corresponding virtual channel indicator, and wherein said pointers and labels are mapped into one or more separate asynchronous cells for transport ahead or said traffic cells.

Communications network

In a label switch communications network, a third level of label is employed in conjunction with a dynamic multiplex constraint-based routed label switched path (CR-LSP) in order to achieve implicit switching at nodes within the network. Implicit switching occurs when a switching function takes place at a node without the need for any control function being required at that node. A three-layer label stack provided at the edge of the network achieves end-to-end connection oriented behaviour with guaranteed Quality of Service. The use of the three-layer label stack concentrates the control of the network to the two edges of the network and a single central switching stage of the network.

An interface arrangement provides interfacing between a frame based telecommunications network in which traffic is transported in frames and an asynchronous network in which traffic is transported in cells or packets. Each TDM frame supports a plurality of data structures each comprising one or more channels. Credits corresponding to bandwidth entitlement are issued at a substantially constant rate and are assigned to the data structures according to the size of those structures by a connection control. Each data structure is accorded a threshold number of assigned credits, and when this number has been reached, the data structure is assembled into cells or packets for dispatch into the asynchronous network.

Asynchronous scheduler

A method and apparatus for handling persistence measurement of channel associated signaling for a plurality of line circuits, eg, T1, E1, OC3, STM 1 circuits, which extracts channel associated signaling data from a plurality of line circuits; assembles the channel associated signaling data into a data frame; contains the data frame in a suitable carrier, eg, an AAL 0 cell; monitors a continuous stream of the data frames, to check for changes in line status; and generates an event message data frame when a persistent change of line state has been detected. The extracting of associated signaling data may be provided on a separate card to a call control processor, and using separate processor functionality. A data processing load of a prior art call control processor which would otherwise be taken up in channel associated signaling persistence measurements may be alleviated, and the data processing burden on a prior art call control processor for handling persistence measurements is separated off and handled by the data processing apparatus and method according to the present disclosure.

Automated line signal processing

A communications multi-service network arrangement for transporting information packets from a user station to a destination comprises a label switched core network constituted by a plurality of abstract nodes interconnected by tunnels. Each abstract node comprises one or more real nodes. An access network provides user access to the core network. A route across the core network comprises a plurality of label switched path sections specified in terms of a sequence of abstract nodes, the route being identified by a label stack identifying a quality of service capable connection from the end station via the access network to the core network and across the core network to a destination.

The invention relates to a method and apparatus for multiplexing traffic from a plurality of fixed bit rate sources over an ATM network. The traffic from the fixed bit rate users is multiplexed to form a TDM trunk group which is assembled into AAL2 minicells prior to being converted to ATM cells for transmission on the ATM network. By combining the fixed rate traffic sources into a TDM trunk group and then mapping the trunk group into AAL2 minicells, it is possible to improve efficiency of fixed bit rate traffic transmission using the ATM protocol.

On receipt of a request for a communication session over a communications network, such as an Internet Protocol communications network, a path for the session is established. In a preferred example the communications network is an MPLS network and the method uses a modified version of the SIP messaging protocol. Bandwidth along a chosen path is reserved and a messaging protocol such as CR-LDP used to establish this reserved path for the communication session. Internet protocol and MPLS communications networks typically only support uni-directional flows. Several methods for establishing bi-directional communication sessions over internet protocol communications networks that use MPLS connections are described. This is particularly useful for telephony applications using internet protocol communications networks. In a preferred example, the established connection provides a guaranteed level of quality of service.

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Stanstead Abbotts, United Kingdom

David John Stacey