2979results about "Circuit switching systems" patented technology

A method and apparatus are provided that allows for the representation of a larger number of classes of network traffic and logical queues than is physically available on a per port basis within a network device. A number of logical queues, whose number can match the number of classes of network traffic a network device handles, may be supported across an aggregated set of ports even though the network device has fewer physical queues per port than there are classes of network traffic. The method and apparatus improve the management of network traffic sensitive to time delay and jitter, and further facilitates the operation of these applications in a simultaneous or near simultaneous manner.

Reduction of administrative overhead in maintaining network information, rapid convergence on an optimal routing path through the data network, and utilization of only required network resources are realized by a novel method for establishing a call path between network users. The method is based upon deployment of a network information server that stores network topology information and that is addressable by each end user. In this method, the network information server receives a request to establish a call path. The request identifies at least the calling party. In response to the request, the network information server determines a network traversal between the calling party and a root network wherein the network traversal includes call path information about the sub-networks between the calling party and the root network. The request for establishing a call path can also identify the called party. Based on the calling and called party identification, the network information server also determines a second network traversal between the called party and the root network. The second network traversal is sent to either the calling party or the called party or to both the calling and called parties. The server can determine an intersection of the traversals and send the intersection information to the parties. The intersection information is known as a merge point and represents an optimal call path between the parties.

The invention provides a method and apparatus for re-ordering data traffic units, such as IP data packets, that may have been miss-ordered during a transmission over a multi-pathway link between a source node and a destination node in a network. The re-ordering apparatus includes a storage medium for intercepting the IP data packets and holding the IP data packets to allow IP data packets delayed on slower pathways to catch-up. The IP data packets in the storage medium are re-ordered based on their sequence number in an attempt to restore the original order of the IP data packets. A maximal time delay variable determines how long a certain IP data packet can be held in the storage medium. The TP data packet is released prior to the maximal time delay variable or as the maximal time delay variable is exceeded.

A method and system of performing IP multicast includes a client at one of many downstream networks that sends a request signal to an upstream network via a return channel (e.g., the Internet), and the upstream network sends the request to a media server. The media server, and for live data, a media encoder, processes a media stream to generate a real-time IP multicast communication that is output to a unidirectional satellite that transmits the IP multicast communication to the client without delay via the downstream network, and can convert the IP multicast to unicast. The bidirectional return channel allows the source to calculate billing information based on client usage statistics, and transmits confirmation acknowledgement based on a confirmation request from the upstream network. Because the routing configuration is transparent to the rest of the network, the invention applies to multi-hop networks on both sides of the satellite link.

Methods and apparatus are disclosed for generating and using an enhanced tree bitmap data structure in determining a longest prefix match, such as in a router, packet switching system. One implementation organizes the tree bitmap to minimize the number of internal nodes that must be accessed during a lookup operation. A pointer is included in each of the trie or search nodes to the best match so far entry in the leaf or results array which allows direct access to this result without having to parse a corresponding internal node. Moreover, one implementation stores the internal node for a particular level as a first element in its child array. Additionally, one implementation uses a general purpose lookup engine that can traverse multiple tree bitmaps or other data structures simultaneously, and perform complete searches, partial searches, and resume partial searches such as after receiving additional data on which to search.

A system and method for performing messaging between telephones in a data network telephone system. The message communications may be managed by a messaging application connected to the data network. The messaging application detects when a telephone is connected to another telephone and sends a messaging input screen to the first telephone. The messaging application may determine the availability of other users for messaging and may control messages communicated between the first telephone and the other users. The messages may be text or voice messages.

Provided is a system and method for a multicast routing algorithm to work in infrastructure based mesh networks. It chooses access points, fixed infrastructure gateway nodes connected to each other and/or the global internet via a wired/wireless backbone, as a group of local multicast group leaders to form a multicast group leader cloud. Each local multicast group leader is elected on-demand according to the local multicast group member's request. Each local multicast group leader forms a local multicast tree rooted at this leader connecting all multicast group members associated with the AP. The processes of electing and maintaining local multicast trees rooted at APs enable efficient coordination with underlying unicast routing to exploit the advantages of fixed infrastructure nodes. Therefore, routing overhead and multicast tree convergence time are reduced. The method can support large networks with fast topology change due to fast convergence and reduced routing overhead.

The invention provides unique architectures and techniques for routing redundancy in a data switch configured to use label switching. Multiple label switch controllers (LSCs) each operate concurrently but independently of each other to provide routes through a data switching mechanism. Preferred embodiments provide a plurality of LSCs offering MPLS capabilities coupled to a single switch, such as an ATM switch. The similarly configured LSCs each can concurrently support a route for data (e.g., labeled ATM cells) within the data switching mechanism in parallel, thereby providing the ability to support redundant and multiple parallel data networks. The configuration is called a label switch router (LSR). A fully-meshed embodiment allows selected routes to share bandwidth on ports, while a fully parallel embodiment provides separate ports for selected routes. Since each LSC provides parallel routes with the other LSCs in an LSR, a communications between an LSR and a label edge router (LER) can use multipath routing to concurrently distribute data equally across the parallel routes for each destination. Alternatively, unipath routing techniques can select one route for use for each destination from the available routes concurrently offered by each LSC. In the event of a failure of one of the LSCs, multipath routing implementations can exclude transmission of data onto the failed network, while continuing to use the other parallel networks supported by non-failed LSCs in a concurrent manner. Alternatively, if a failure occurs with unipath routing, a new route offered by another LSC can be selected for data transfers. In either case, the LSC that fails does not need to provide state or connection information to the LSCs that operate subsequently to the failure, since they are already configured in parallel to support the same route. Upon an LSC failure, switch resources such as bandwidth that were used by the failed LSC are made available to the remaining non-failed LSCs. The design allows failures are handled gracefully without diminished network capacity or data loss resulting in a highly reliable routing capability provided within connection-based or circuit-switched networks.

A system and method for ensuring that packets are not switched out of order in a network switch capable of dynamically selecting different routing techniques. The network switch may include multiple input ports, multiple output ports, and a shared random access memory coupled to the input ports and output ports by data transport logic. The switch may route packets using cut-through routing or early-forwarding. To ensure that packets are not switched out of order, sequence numbers may be assigned to packets as the packets are received at one of the input ports. A different sequence may be used for each output port. The output port may also track sequence numbers by storing the number corresponding to the most recently received packets from each input port. The stored value may compared with a sequence number assigned to a packet to ensure that they are within one before allowing cut-through routing.

In accordance with embodiments, there are provided mechanisms and methods for creating, exporting, viewing and testing, and importing custom applications in a multi-tenant database environment. These mechanisms and methods can enable embodiments to provide a vehicle for sharing applications across organizational boundaries. The ability to share applications across organizational boundaries can enable tenants in a multi-tenant database system, for example, to easily and efficiently import and export, and thus share, applications with other tenants in the multi-tenant environment.

Apparatus and methods using a first service provider such as a WAN cellular service provider to initiate a communications exchange between a plurality of communications units and a second service provider such as WLAN service provider to provide enhanced communications services to the units has been disclosed and described.

Methods and systems for determining paths for flows within a multi-stage network made up of clusters of processing nodes. The flow paths may be determined without knowledge of whether or not packets of a particular flow will actually traverse specific ones of the clusters within the multi-stage network. In various implementations, the nodes of the multi-stage network may be coupled to one or more physical network switches through respective physical interfaces and a virtual connectivity grid superimposed thereon and configured through the use of a flow routing framework and system management framework to group the nodes into a number of clusters. The nodes of each cluster are configured to perform similar packet processing functions and the clusters are interconnected through virtual networks to which the nodes are communicatively coupled via virtual interfaces overlaid on top of the physical network interfaces.

The present invention sets forth a network-centric service distribution architecture and method that integrates a wireless access system/service in the residence, SOHO, business or public environment through the use of a local broadband network, such as a Residential-Business Broadband Network (RBN), to the service provider's broadband transport network and to a service provider's broadband packet network that facilitates end-to-end packet telecommunication services. Access functions for connecting said service provider's broadband packet network to the RBN via said service provider's broadband transport network are provided. Call and service termination functions to a plurality of local RBN devices are also provided. Signals from a plurality of wireless devices are accepted and forwarded to an IEEE 802.11b interface for a wireless modem and/or to an Ethernet interface for a Voice over Internet Protocol (VOIP)/Ethernet Processor, where the forwarded signals comprise intranet telephony and data. Voice signals are also accepted from a plurality of tip/ring interfaces and forwarded to a broadband transport interface for back haul of data and voice packets. A service provider can deploy services in an integrated voice, data and multimedia environment cost-effectively based on one broadband packet network.

A method and system for conveying an arbitrary mixture of high and low latency traffic streams across a common switch fabric implements a multi-dimensional traffic classification scheme, in which multiple orthogonal traffic classification methods are successively implemented for each traffic stream traversing the system. At least two diverse paths are mapped through the switch fabric, each path being optimized to satisfy respective different latency requirements. A latency classifier is adapted to route each traffic stream to a selected path optimized to satisfy latency requirements most closely matching a respective latency requirement of the traffic stream. A prioritization classifier independently prioritizes traffic streams in each path. A fairness classifier at an egress of each path can be used to enforce fairness between responsive and non-responsive traffic streams in each path. This arrangement enables traffic streams having similar latency requirements to traverse the system through a path optimized for those latency requirements.

A pipelined linecard architecture for receiving, modifying, switching, buffering, queuing and dequeuing packets for transmission in a communications network. The linecard has two paths: the receive path, which carries packets into the switch device from the network, and the transmit path, which carries packets from the switch to the network. In the receive path, received packets are processed and switched in an asynchronous, multi-stage pipeline utilizing programmable data structures for fast table lookup and linked list traversal. The pipelined switch operates on several packets in parallel while determining each packet's routing destination. Once that determination is made, each packet is modified to contain new routing information as well as additional header data to help speed it through the switch. Each packet is then buffered and enqueued for transmission over the switching fabric to the linecard attached to the proper destination port. The destination linecard may be the same physical linecard as that receiving the inbound packet or a different physical linecard. The transmit path consists of a buffer/queuing circuit similar to that used in the receive path. Both enqueuing and dequeuing of packets is accomplished using CoS-based decision making apparatus and congestion avoidance and dequeue management hardware. The architecture of the present invention has the advantages of high throughput and the ability to rapidly implement new features and capabilities.

A method of routing a message from a source node to a destination node in an adhoc wireless network comprising a plurality of nodes, comprising the steps of; transmitting a first message from the source node to the destination node, receiving said first message at said destination node, transmitting a second message from said destination node in response to the first message and, wherein at least one of said first message and said second message is sent between the source and destination nodes via a plurality of paths comprising at least one intermediate node, selecting a path for communication between the source node and the destination node using an indication of the time taken for at least one of said second and first messages to propagate between each node on each path.