Lucent Technologies Inc.

At+t Corp.

Polytechnic University

Other

American Telephone and Telegraph, Co.

At&t Ipm Corp.

Malathi Veeraraghavan

Thomas F La Porta

Mark John Karol

Kai Y Eng

Clark B Woodworth

Madhukar M Kshirsagar

Gopal Krishna Dommety

Ramachandran Ramjee

David Hilton Shur

Santhanam Srinivasan

Pramod Pancha

Deepak Kataria

David Michael Rouse

Dimitris Logothetis

Ramesh Karri

Laura Ellen Adams

Ender Ayanoglu

Gagan Lal Choudhury

Robert J Munoz

Zhao Liu

Irene Katzela

Brian Douglas

Reinette Grobler

Haobo Wang

Timothy Christopher Moors

Transferring data (such as files) on an end-to-end, high-speed packet-switched network connection (a 'virtual circuit') or on a circuit. An out-of-band path is used for signaling and status messages (control). The same, or a separate, out-of-band path may be used to retransmit chunks of data that were received with errors or that were not received at all. By simplifying the data being sent over the high-speed (virtual) circuit, the resources of the (virtual) circuit are used efficiently since less overhead is required. Further, since the size of the file to be transferred can be predetermined, and since any retransmissions can be made over a path other than the (virtual) circuit, the (virtual) circuit that best meets the needs of the data transfer can be selected, thereby further increasing the efficiency with which the (virtual) circuit is used.

Transferring data such as files

A call signaling protocol that uses simplified messaging to set up, confirm set up, tear down, and confirm tear down of a connection. The available capacity of communications links is tracked so that it can be quickly determined whether or not a link can handle a call. Segments (e.g., time slots, wavelengths, etc.) of a link having enough available capacity are allocated by a separate operation. Connection state information is also tracked. The simple messages and information used by the signaling protocol permits it to be easily implemented in hardware. Such an implementation enables high-speed, high-capacity, call signaling.

Signaling for reserving a communications path

A method of automatically queuing calls for later transmission in connection-oriented networks instead of blocking them when network resources are unavailable at the time the request is received, as currently done. A simple call queuing method holds up call setup messages at each switch along an end-to-end path of a network until resources become available. This simple, known queuing method suffers from poor network utilization and long call queuing delays. However, if calls that can be queued have known holding times, a call scheduling method that results in reduced call queuing delays and improved network utilization according to the present invention can be realized.

Scheduling of calls with known holding times

A connectionless packet network and an optical WDM network are interconnected by one or more optical interface modules (gateways) that include both optical to electrical interfaces, as well as a connection management module, or control element, that is arranged to control the OADM's and the configuration of lasers and port assignments within the gateways, such that a route through the optical network to a desired endpoint is selected. The OADM's can be programmed, (i.e., locally or remotely controlled by the control element) such that the wavelengths that can be added or dropped by an OADM can be changed, thereby allowing routes to be established through the optical network, from an originating gateway to a destination gateway. In addition, the optical interface modules can include a plurality tunable lasers that can be controlled such that routes can be established through the optical network without requiring changes to the routing table that associates particular endpoints with particular ports. The system can be operated in a &ldquo;provisioned&rdquo; mode, where connections are set up a priori (i.e., before actual traffic flow starts), or in a &ldquo;switched&rdquo; mode, where connections are set up on a session by session (call by call) basis. The interface modules can be integrated with the components otherwise present in conventional packet routers, or housed separately in intelligent gateways that interconnect conventional packet routers with OADM's on an optical WDM network.

WDM optical networks arranged for internetworking with packet networks

Disclosed is a location management method for a communication network. In a first embodiment, a procedure for finding an optimal path between a calling switch and a visiting switch node is integrated in the call set up procedure. The connection set up procedure starts by setting up a connection path between the calling switch and the home switch. Then, an &ldquo;optimal crossover node&rdquo; is determined along the connection path and then the connection path is cranked back starting from the home switch and moving towards the optimal crossover node. Once the optimal crossover node is reached, the a connection set-up proceeds to set up a connection between the optimal crossover node and the visiting switch. In an alternative embodiment, first a connection is set up between the calling switch and the home switch. Then the connection is extended to the visiting switch either by the call-forwarding or by two-phase crankback method. This results in a quickly routed, but sub-optimal connection. Once the connection extension is completed by call forwarding or by the two phase crankback scheme, the route is optimized by selecting a segment on the sub-optimal connection for route optimization and then utilizing the method of the first embodiment to establish an optimally routed connection.

Method for location management in a communication network

An address interworking system and method for an internetwork that includes a first network using first network addressing communicating via one or more internetworking gateways with a second network using second network addressing. The gateways register one or more first network addresses in the second network as first network address-encapsulated or- mapped second network addresses. Reachability information regarding the first network-encapsulated or -mapped second network addresses is then disseminated through the second network. When a communication request containing a first network destination address is received from the first network at one of the gateways, the receiving gateway performs encapsulation or mapping of the first network destination address into a first network-encapsulated or -mapped second network destination address. It then routes a communication request containing the first network-encapsulated or -mapped second network destination address through the second network based on said disseminated reachability information.

Interworking of addressing in an internetwork

Arrangements and methods for improving the probability of finding a connection path that meets user specified delay requirements. The improvements offer packet switches enhanced path selection that will improve the resource utilization of networks, both flat networks and hierarchical networks incorporating such switches. The latter type of networks run the path selection algorithm in the PNNI v1.0 standard where the packet switches are asynchronous transfer mode switches. Two modes of enhanced delay-based path selection are based on two different accumulation methods, namely an additive method and an asymptotic method.

Quality of service based path selection for connection-oriented networks

A handoff scheme for a communications network is disclosed. In a first embodiment a procedure for finding an optimal path between an originating network node and a destination network node is integrated in the handoff procedure. An optimally routed connection is obtained by first determining an optimal &ldquo;crossover node&rdquo; along the existing path and then the handoff is effected by altering the existing connection route so that it travels along the existing path until it reaches the crossover node, where the path then varies from the original route, and a new segment between the crossover node and the new location is established. Then the call is switched to the new segment and the corresponding old segment on the old connection is released. In an alternative embodiment, the handoff procedure is performed first by completing a fast reroute connection using a prior art path extension method. This results in a quick, but sub-optimal handoff connection. Once the handoff is completed, the route is optimized by selecting a segment on the sub-optimal connection for rerouting and then utilizing the method of the first embodiment to establish an optimally routed connection.

Method for rerouting and route optimization for handoff management in a communications network

Traffic on a connectionless (CL) network, such as IP packets, can be routed onto a connection a connection oriented (CO) network, such as an ATM telephony network, when it is advantageous to do so from a user or service provider viewpoint, without affecting the ability of users to continue to use existing applications. Routing is controlled by nodes called CL-CO gateways, with connectivity to both the CL network and the Co network. When CL traffic originating at a source reached these gateway nodes, a decision is made whether to continue carrying the information in the CL mode, or to redirect the traffic to a CO network. In accordance with one embodiment of the present invention, each CL-Co gateway includes hardware and software modules that typically comprise (a) interfaces to the Co network, (b) interfaces to the CL network (c) a moderately sized packet buffer for temporarily storing packets waiting for CO network setup or turnaround; (d) a database for storing forwarding, flow control header translation and other information, and (e) a processor containing logic for controlling the gateway packet handling operations.

Technique for internetworking traffic on connectionless and connection-oriented networks

A communications system for transporting connectionless datagrams over a connection-oriented network is arranged to remove the address resolution function and the connection setup function from a sending host and combine them in a third-party connection server in conjunction with channel management at connection-oriented routing points. The third party request protocol can be used for Classical connectionless over a connection oriented network, legacy LAN emulation and Routing Over Large Clouds.

Communications system for transmission of datagram packets over connection-oriented networks

Methods and communication networks having a plurality of connection-oriented switches in which administrative weights are assigned based on link call blocking probabilities. Three assignment schemes include, first, a solution that can be built in the switch software of sufficiently similar switches to enable the switches to determine administrative weights for their links. The second and third schemes employ administrative weight management stations. The second scheme uses an administrative weight management station that operates to enhance total network revenue or throughput in a communication network in which all of the switches implement a certain type of accounting management information databases (MIB). The third scheme uses an administrative weight management station that computes administrative weights for switches that do not have the capability for the second scheme, but which employ appropriate MIBs.

Administrative weight assignment for enhanced network operation

This is a method for dynamic and distributed management of Virtual Path Connections (VPCs) in a hierarchical ATM network. VPC parameters, including VPC type (heterogeneous or homogeneous), source node characteristics, end-to-end VPC constraints (GoS and QoS), and the number of on-demand connections to be supported, are determined or specified. Network resources, such as bandwidth and buffer size availability, are also determined. The parameters and information relating to the network resources are sent to a connection server that computes an optimal physical route for the VPC, allocates resources along the computed route, and notifies switches along the route of the new allocation of resources. The switches then change their respective configurations to accommodate the new allocation.

Virtual path management in hierarchical ATM networks

A facility is provided in which an ATM switch may operate as a switch in the provision of connection oriented services and operates as a router in the provision of connectionless services. In the router mode, the ATM switch may determine 'on the fly' a route which may be used to forward received data cells to an intended destination and then forwards each of the data cells in sequence over the determined route. In the switch mode, the ATM switch operates conventionally and forwards a received data cell over a previously defined switched virtual path. In certain cases, the ATM switch may operate as a router only.

Connectionless message service using ATM routers

The present invention is a user process that resides in network nodes to act as an agent for mobile terminals in, for example, PCS environments. The user process handles negotiation and complex signaling functions for the user, thus reducing the amount of signaling traffic that must travel over the valuable air interface. To achieve low call establishment times the user process is migrated as user move. Three embodiment is adapted to enable data sizes which are to be transferred to be optimized, leading to low overhead. This approach also provides flexibility when migrating across heterogeneous environments. A second alternative embodiment may be advantageously utilized when a program is compute intensive and asynchronous migration is essential. The third embodiment provides high reliability in the form of checkpointing, but incurs a high migration delay and has high memory requirement for network processors.

Growing community of inventors

Atlantic Highlands, NJ, United States of America

Malathi Veeraraghavan