Nortel Networks Corporation

Northern Telecom Limited

Rockstar Consortium US LP

Roy Harold Mauger

Simon Daniel Brueckheimer

Julian Frank Barry Cable

Mark Robert Gibson

David John Stacey

Clive Colin Hayball

Dave J Stacey

James Alexander Shields

Desne Jean Rose

Mark Ashworth

Sarah Lucy Wright

Robert Friskney

Brian Michael Unitt

Julian Frank Cable

Catherine Rosenberg

Robert John Dean

Stephen Leonard Fagg

Stephen Rylant Evans

Simon Daniel Breuckheimer

Stephen Rhylant Evans

Steve Leonard Fagg

Allen William Oliver

Daniel Vincent McCaughan

Gary Robert Kirkpatrick

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

To ensure an effective mechanism for disaster recovery, system migration and network enlargement, a communication system (FIG.) comprises a narrowband-to-broadband interface () having a plurality of network adaptors (-) interconnected to a switch (-) that provides access to a plurality of virtual channels (-) supported by a broadband network. The plurality of network adaptors (-) are also coupled to a plurality of trunks (-) that each support at least one of a plurality of different communication functions. At least two call servers (-) are independently coupled to the narrowband-to-broadband interface () and are arranged to control interconnection of trunks to virtual channels, while each of the at least two call servers is responsible for controlling interconnections of group of trunks that share a common communication function within each group. Communication system functionality is therefore separated between the at least two call servers.

Communication system architecture and operating methods thereof

Narrowband subscriber terminals () of different narrowband networks are interconnected via a broadband network () that supports dissimilar signaling protocols to those maintained on the respective narrowband networks (). A call server in a first narrowband network (), in response to a call () from a first subscriber terminal () to a second subscriber terminal () in a second but different narrowband network (), selects a phantom trunk () between the two networks. The phantom trunk has a unique circuit identity, which circuit identify is used in a first instance to relay to the second network an address of the second subscriber terminal (). Then, in a second instance, the unique circuit identify is used to relay to the second network an address of the first subscriber terminal (). By recognizing that two connection requests have been received at opposite ends of the same phantom trunk, a processor in the second network is able to determine that a direct connection between the first and second subscriber terminals is required through the broadband network ().

System and method for establishing a communication connection

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.

In a packet communications network system, a border gateway protocol is employed to route an information packet from a source in a first autonomous system via a first label switched path to a destination in a second autonomous system via first and second border routers at an interface between the first and second autonomous systems. A label stack attached to the packet identifies both a forwarding interface for the packet and a forwarding behaviour at that interface. This provides a mapping from the first label switched path on to a second label switched path to the destination in the second autonomous system. Preferably, the destination router in the second autonomous system returns to the source router in the first autonomous system a two-label stack identifying first and second paths across the first and second autonomous systems respectively.

Routing traffic in a communications network

A label switched path is determined in a communications multi-service network comprising a plurality of nodes interconnected via quality of service capable tunnels to provide a QoS guarantee for a session in which resource availability from the network edge to multiple central stages and resource availability from the multiple central stages to the destination edge are established. A series of quality of service capable tunnels is selected by offering a plurality of candidate central stages to the destination edge and allowing the destination edge to select a complete path across the network. A label stack comprising a set of four labels is attached to a payload to define a selected sequence of tunnels.

Communications network

The invention provides a plurality of core nodes establishing a multi-service transport network, and service nodes each coupled to a core node for providing access to the transport network. A network management system is arranged to define and manage one or more virtual public/private networks within the communications network. Groups of core nodes are configured as abstract nodes within which any available path may be selected to achieve a requested connection. End to end label switched paths are established via the management system by specifying a series of abstract nodes.

Label switched paths are installed in a label switched communications packet network. Paths are selected by defining and installing partial routes each having two or more paths such that an end-to-end route across the network can be defined as the concatenation of two partial routes. Signalling to select a path is effected by sending a path message from an end point to a first virtual router, determining a path from the end point to the virtual router, and forwarding an identity of the path to a second virtual router. The second virtual router determines a routing vector across the network, and returns information identifying the routing vector to the first virtual router.

Label switched traffic routing and signaling in a label switched communication packet network

A method for enabling traffic to be carried between devices which may use different communications protocols employs a multimedia service provide, which provides an interface between two devices or between a device and a multimedia network. The service provider enables conversion between the communications protocols used by the two devices by comparing the protocols used by each device and, preferably, carrying out a conversion which minimises the amount of traffic conversion required. If two devices are interfaced to an intermediate network via respective service providers, the service providers preferably negotiate before communication between the devices begins to ensure, if possible, that traffic conversion is only performed by one of the service providers. Each device is connected to the service provider at a network access server of a type matched to the device type and traffic conversion is carried out as required using an Asynchronous Transfer Mode Virtual Channel switch controlled by a multimedia server.

Communications method and apparatus

To ensure an effective mechanism for disaster recovery, system migration and network enlargement, a communication system (FIG.) comprises a narrowband-to-broadband interface () having a plurality of network adaptors () interconnected to a switch () that provides access to a plurality of virtual channels () supported by a broadband network. The plurality of network adaptors () are also coupled to a plurality of trunks () that each support at least one of a plurality of different communication functions. At least two call servers () are independently coupled to the narrowband-to-broadband interface () and are arranged to control interconnection of trunks to virtual channels, while each of the at least two call servers is responsible for controlling interconnections of group of trunks that share a common communication function within each group. Communication system functionality is therefore separated between the at least two call servers.

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.

A telecommunications network architecture provides transport and switching of user services, particularly PSTN/ISDN services. In the network, connections are set up between end points which typically comprise narrow band exchanges serving subscribers. Calls are set up between the end points via call servers using e.g. ISUP signalling between the end points or exchanges and the call servers. The call servers set up connections via a concatenated series of paths or tunnels across an intermediate MPLS network via media gateways serving respective nodes in the MPLS network. User information packets are carried across the MPLS network by the attachment of an appropriate label, this label being removed on egress from the MPLS network to recover the original packet.

Supporting multiple services in label switched networks

A network arrangement for delivering IP services to subscribers includes a core network, a plurality of label switched media gateways coupled to the network and each providing an interface for one or more subscriber terminals. Call servers associated with the network are used to establish connections between pairs of gateways, these connections being routed across the core network via tunnels established therein. The tunnels are exclusively reserved for traffic between the label switched media gateways so as to provide security of that traffic from third party access and to provide a guaranteed quality of service. Because traffic is accepted into a tunnel only if bandwidth is available in that tunnel, firm and meaningful quality of service guarantees can be given to users.

Label switched media gateway and network

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.

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.

Growing community of inventors

Radlett, United Kingdom

Roy Harold Mauger