Abstract: In a fast optical switch comprising a plurality of star couplers, channel switching, Time Division Multiplex (TDM) switching, or both may be provided. The operation of the fast optical switch is enabled by a fast scheduler comprising at least two scheduler modules. The throughput of the optical switch may be increased through a process of bimodal pipelined connection-packing.

Abstract: A fast optical switch is needed to realize an economical and scaleable optical-core network. In the disclosed optical switch, switching is effected by rapid wavelength conversion. Either channel switching, Time Division Multiplex (TDM) switching or both may be provided by the fast optical switch. The operation of the fast optical switch is enabled by a fast scheduler. The throughput of the optical switch may be increased through a process of bimodal pipelined connection-packing. An in-band exchange of control signals with external nodes may serve to minimize the control overhead. Such control signals may include time-locking signals and connection-requests. A modular structure may be configured to comprise several fast optical switches to yield a high-speed, high-capacity, fully-connected optical switch.

Abstract: A method of interleaving time-critical data packets and delay-tolerant data packets on a shared channel emanating from a control port of a switching node permits a strict time requirement for transmission of time-critical data packets to be met. A control circuit of the switching node stores a local time, an indication of a time required to transfer a delay-tolerant data packet waiting to be transferred, a comparator and a selector to control transfer of the time-critical and delay tolerant data packets.

Abstract: A method and a network for a universal transfer mode (UTM) of transferring data packets at a regulated bit rate are disclosed. The method defines a protocol that uses an adaptive packet header to simplify packet routing and increase transfer speed. The protocol supports a plurality of data formats, such as PCM voice data, IP packets, ATM cells, frame relay and the like. The network preferably includes a plurality of modules that provide interfaces to various data sources. The modules are interconnected by an optic core with adequate inter-module links with preferably no more than two hops being required between any origination/destination pair of modules. The adaptive packet header is used for both signaling and payload transfer. The header is parsed using an algorithm to determine its function. Rate regulation is accomplished using each module control element and egress port controllers to regulate packet transfer.

Abstract: The present invention enables fast reconfiguration of paths associated with bufferless core nodes in a network where any two edge nodes may interconnect through a core node. In order to enhance network agility and performance, edge nodes associated with a core node are separated into a plurality of groups based on, for example, round-trip delay from the core node. This separates the short-haul paths from the long haul paths, thereby enabling the short-haul paths to be configured more frequently than the long-haul paths. It is preferable that the periods be set such that each additional period is an integer multiple of the previous one. This allows for simultaneous configuration of groups of paths. Although the methods and apparatus of the present invention are most effective for bufferless optical switches, they are still effective for electronic switches which may be bufferless or equipped with input data buffers.

Abstract: A method of interleaving time-critical data packets and delay-tolerant data packets on a shared channel emanating from a control port of a switching node permits a strict time requirement for transmission of time-critical data packets to be met. A control circuit of the switching node stores a local time, an indication of a time required to transfer a delay-tolerant data packet waiting to be transferred, a comparator and a selector to control transfer of the time-critical and delay tolerant data packets.

Abstract: A multi-stratum multi-timescale control for self-governing networks provides automatic adaptation to temporal and spatial traffic changes and to network state changes. Microsecond timescale reacting through the routing function, a facet of the lowest stratum, allows a source node to choose the best available route from a sorted list of routes, and to collect information on the state of these routes. Millisecond timescale correcting through the resource allocation function, a facet of the intermediate stratum, allows the network to correct resource allocations based on requirements calculated by the routing function. Long-term provisioning through the provisioning function at the higher stratum allows the network to recommend resource augmentations, based on requirements reported by the resource allocation function. The control is implemented in the network through coordination across edge node controllers, core node controllers, and network controllers.

Abstract: A method and a network for a universal transfer mode (UTM) of transferring data packets at a regulated bit rate are disclosed. The method defines a protocol that uses an adaptive packet header to simplify packet routing and increase transfer speed. The protocol supports a plurality of data formats, such as PCM voice data, IP packets, ATM cells, frame relay and the like. The network preferably includes a plurality of modules that provide interfaces to various data sources. The modules are interconnected by an optic core with adequate inter-module links with preferably no more than two hops being required between any origination/destination pair of modules. The adaptive packet header is used for both signaling and payload transfer. The header is parsed using an algorithm to determine its function. Rate regulation is accomplished using each module control element and egress port controllers to regulate packet transfer.

Abstract: A self-configuring distributed switch is disclosed. The switch comprises a channel switch core connected by a plurality of channels to a plurality of high-capacity data switch modules. A global controller selects paths through the channel switch core and reconfigures the paths in response to dynamic changes in data traffic loads. Propagation delays between the data switch modules and the channel switch core are coordinated to keep reconfiguration guard time minimized. The advantage is a very high-capacity, load-adaptive, self-configuring switch that can be geographically distributed to serve a large geographical area.

Abstract: This invention relates to the design of a scaleable high performance multiservice network based on programmable transport. A meshed network with dynamically-adjustable link capacities and nodes which provide data packing into “containers” for transport is proposed. A ring-based network, exchanging data containers among its nodes, is the preferred implementation, due to its flexibility, maintainability, and high reliability. With lossless rings, the quality of service is controlled solely by the origin and destination nodes, without any interference from other data streams. Flexible programmable transport greatly improves the performance, simplifies the controls, and facilitates scaleability. The concept is a departure from classical network thinking. By reducing the complexity of the network core, an economical, reliable, and manageable network with feature-rich edge nodes can be realized.

Abstract: Rather than restricting a stream of data to a single channel within a multi-channel link between a source node and a core node, each channel is divided into time slots and the stream of data is distributed among these time slots in several channels. However, to ease the management of switching the stream of data at the core node, simultaneous time slots in each channel may be arranged into “stripes,” such that a particular stripe may only include data segments having a common destination. Switching these stripes of data at the core node requires that the source of such a stripe arrange the frame according to a frame structure provided by the core node. Advantageously, where the frame is striped across an entire link, the present invention provides for a variation on link switching that approaches the topological reach of TDM switching while maintaining relatively straightforward operation at the core node.

Abstract: A self-configuring distributed switch has agile core modules connected by a plurality of channels to a plurality of large capacity edge modules. A core module controller selects paths through an associated core module and reconfigures the paths in response to dynamic changes in data traffic loads. Switching latency in the core modules is masked so that the source edge modules need not disrupt data transmission during reconfiguration. Surplus capacity is provided in the core modules to facilitate reconfiguration. Connection release and connection setup policies increase occupancy variance among the space switches in each core module to further facilitate reconfiguration. The reconfiguration functions of the data switch modules and the core modules are coordinated to keep reconfiguration guard time minimized. The advantage is a high capacity, load-adaptive, self-configuring switch that can be geographically distributed to serve a large geographical area.

Abstract: A multi-class digital network is described. The network supports a plurality of digital services using dynamically-configured service bands to support various transport modes and qualities of service. A network control element receives traffic and network state information from the nodes. The network control element maintains a network topology and uses the network topology to compute route sets for the nodes. The network control element uses the traffic information to compute network size specifications. The switching nodes use rate controllers to divide the capacity of each link among the connection classes according to rules which ensure consistent service attributes for each band across the network. The rate controllers are adapted to support different transport modes and different packet sizes so that the deconstruction and reconstruction of packets at network edge devices is eliminated.

Abstract: At a master controller of a space switch in a node in a data network, a request is received from a source node that requests a connection to be established through the space switch. This request is compared to other such requests so that a schedule may be established for access to the space switch. The schedule is then sent to the source nodes as well as to a slave controller of the space switch. The source nodes send data bursts which are received at the space switch during a short guard time between successive reconfigurations of the space switch. Data bursts are received at the space switch at a precisely determined instant of time that ensures that the space switch has already reconfigured to provide requested paths for the individual bursts. The scheduling is pipelined and performed in a manner that attempts to reduce mismatch intervals of the occupancy states of input and output ports of the space switch.

Abstract: Methods and apparatus for transferring data segments of a data stream across multi-channel links in a high-capacity network, so that the segments are equitably smeared across the channels of each multi-channel link, are described. The high-capacity network comprises a multiplicity of distributed high-capacity edge nodes interconnected by multi-channel links to a plurality of core nodes. Each edge node comprises a source node and a sink node which may share memory and control. A path from a source node of a first edge node to a sink node of a second edge node traverses two links, a first link from the source node to a selected core node and a second link from the selected core node to the destination sink node. Tandem switching through an intermediate edge node is not required, even for data streams of very low bit rate.

Abstract: A method and a network for a universal transfer mode (UTM) of transferring data packets at a regulated bit rate are disclosed. The method defines a protocol that uses an adaptive packet header to simplify packet routing and increase transfer speed. The protocol supports a plurality of data formats, such as PCM voice data, IP packets, ATM cells, frame relay and the like. The network preferably includes a plurality of modules that provide interfaces to various data sources. The modules are interconnected by an optic core with adequate inter-module links with preferably no more than two hops being required between any origination/destination pair of modules. The adaptive packet header is used for both signaling and payload transfer. The header is parsed using an algorithm to determine its function. Rate regulation is accomplished using each module control element and egress port controllers to regulate packet transfer.

Abstract: Methods and apparatus for control of a multi-class digital network are described. The network supports a plurality of digital services using dynamically-configured service bands to support various transport modes and qualities of service. Flexible controls with two degrees of freedom are used at the node level to dynamically configure the transport bands. The first degree of freedom is realized using adaptive alternate routing to balance the traffic intensity across the network and, hence, increase the efficiency of the band. The second degree of freedom is achieved through adaptive network partitioning to provide elasticity to the band structure. This permits band capacity to be adaptively reconfigured as connections are added and dropped. The switching nodes use rate controllers to divide the capacity of each link among the connection classes according to rules which ensure consistent service attributes for each band across the network.

Abstract: A method and a network for a universal transfer mode (UTM) of transferring data packets at a regulated bit rate are disclosed. The method defines a protocol that uses an adaptive packet header to simplify packet routing and increase transfer speed. The protocol supports a plurality of data formats, such as PCM voice data, IP packets, ATM cells, frame relay and the like. The network preferably includes a plurality of modules that provide interfaces to various data sources. The modules are interconnected by an optic core with adequate inter-module links with preferably no more than two hops being required between any origination/destination pair of modules. The adaptive packet header is used for both signaling and payload transfer. The header is parsed using an algorithm to determine its function. Rate regulation is accomplished using each module control element and egress port controllers to regulate packet transfer.

Abstract: A fully meshed telecommunications network based on an optical core transport network having a plurality of optical nodes is described. An electronic edge switch is connected to an optical node and dedicated channels are established between all the possible pairs of electronic edge switches through their associated optical nodes and the optical core transport network. Connection paths are set up using a channel or channels between a pair of electronic edge switches which perform major functions concerning connection routes, including rate regulation, path establishment, etc.

Abstract: A flexible global distributed switch adapted for wide geographical coverage with an end-to-end capacity that scales to several Petabits per second (Pb/s), while providing grade-of-service and quality-of-service control, is constructed from packet-switching edge modules and channel-switching core modules. The global distributed switch may be used to form a global Internet. The global distributed switch enables simple controls, resulting in scalability and performance advantages due to a significant reduction in the mean number of hops in a path between two edge modules. Traffic is sorted at each ingress edge module according to egress edge module. At least one packet queue is dedicated to each egress edge module. Harmonious reconfiguration of edge modules and core modules is realized by time counter co-ordination. The global distributed switch can be enlarged from an initial capacity of a few Terabits per second to a capacity of several Petabits per second, and from regional to global coverage.