Abstract: Methods and apparatuses for multiple redundancy schemes in an optical network are described herein. In one embodiment, an exemplary method includes receiving a demand for allocating a first protection path that meets a first set of disjointness constraints with respect to a first working path according to a first protection scheme having a first priority, in response to the demand, locating a second protection path that meets a second set of disjointness constraints with respect to a second working path according to a second protection scheme having a second priority, and assigning the second protection path as a protection path to the first working path if the first priority of the first protection scheme is higher than the second priority of the second protection scheme. Other methods and apparatuses are also described.

Abstract: A method and system for determining path maximum transfer unit (PMTU) in an Internet Protocol (IP) multicast is described. If a packet of a size greater than the MTU of any link of a path, with its Don't Fragment (DF) bit set, is sent by the source, the packet is dropped and an ICMP message, stating “Destination unreachable, DF bit set”, is sent to the source. The rate of messages to the source is controlled to avoid implosion of traffic. In response to the messages, the source sends multicast probe packets of multiple sizes to multicast distribution tree to determine its PMTU.

Abstract: In a method for the conveying of data between several users A, B, in a communications network comprising at least one low-bit-rate artery and one or more standard-bit-rate arteries, the network comprises a basic transmission unit, such as a cell, and at least one adaptation layer protocol, the data to be transmitted taking the form of packets Pi having a size smaller then the size of the basic transmission unit, the method comprising at least the following steps: extracting the packets Pi from the upstream and/or downstream cells of a low-bit-rate artery (steps (4a) or (5a)), inserting said packets according to a given adaptation layer protocol, in the cells of a virtual circuit set up between the ends of the low-bit-rate artery (steps (4b)), or between the users (steps (5b) and (5c)).

Abstract: A method and network element for marking data packets to be transmitted in a packet switched network with a priority information I, the packets being treated in the network according to the priority information I. The priority information I is calculated based on a required bit rate BSIO. The priority information I may be additionally calculated based on a nominal bit rate NBR and on a momentary bit rate MBR, such that a terminal device used with the network element is able to inform the network element in advance about the required bit rate.

Abstract: Radio frequency signals are transmission-reception processed by N antennas. A radio unit performs a frequency translation processing, an amplification processing and an A-D or D-A conversion processing between a baseband signal and the radio frequency signal. A signal processing unit performs a signal processing necessary for the transmission/receiving processing by adaptive array antennas. A modem unit performs modulation/demodulation processings. A baseband unit serves as interface with a network. A control unit controls timings, channel allocation and the like of the radio unit, the signal processing unit, the modem unit and the baseband unit.

Abstract: A system for assisting a user in selecting a packet-based telephony service provider (“PBTSP”) from a group of PBTSPs, and in registering the user with the selected PBTSP for outbound and/or inbound calling. The selection of a particular PBTSP may be stored in a database, and this stored information may be used to enable the user to exchange telephone call data with one of the PBTSPs. One preferred system receives data from the user's computer device, determines whether the user is registered with one the PBTSPs and, if so, transmits data to the computer device which enables it to exchange telephone call data with one of the PBTSPs. The system also receives telephone call data from the computer device, accesses contact information for a PBTSP, and transmits the received telephone call data to the PBTSP using the accessed contact information.

Abstract: A novel method for coordinating the delivery of frames to and the receipt of frames from a power-saving station in a wireless local-area network (LAN) is disclosed. The illustrative embodiment establishes a wake-up schedule for a power-saving station based on a temporal period and temporal offset that reduces the frequency with which multiple stations in a network wake up simultaneously, thereby reducing traffic delays and power consumption. The illustrative embodiment is particularly well-suited to networks with traffic that has delay/jitter quality-of-service (QoS) requirements (i.e., voice calls, videophone calls, etc.).

Abstract: Concurrent testing of NAT connections using different timeout values to compute a keep-alive value for the NAT device. Computation of the approximate timeout value is accomplished concurrently over multiple test connections within about a time equivalent to the actual NAT timeout value. The architecture validates the computation of the approximate timeout value by distinguishing NAT connection failure from external failure using a control connection. Moreover, computation of the keep-alive value is performed only once for a given NAT device rather than being an on-going process for that NAT device. When one of the test connections fails, it is determined that the NAT timeout value is less than the test timeout value associated with the failed test connection. Accordingly, a smaller test timeout value is then selected as the keep-alive value for keep-alive processing of the NAT device.

Abstract: A system for analyzing at least a portion of a telecommunications network is provided. The system includes a traffic flow analyzer 124 operable to (a) assign a plurality of network components to at least first, second, and third component sets 1216, 1220 and 1224, respectively, wherein the first and second component sets correspond to voice communication endpoints; (b) determine bulk voice traffic flows at least one of generated and received by the first and second component sets and passing through the third component set; and (c) based on the bulk voice traffic flow passing through the third component set, determine a requirement for the third component set to realize a selected grade and/or quality of service.

Abstract: Disclosed embodiments reveal techniques for efficiently allocating time slots in a time-division multiplex (TDM) cycle among multiple channels of varying size, particularly when the channels do not all desire an integer number of time slots. TDM cycles can only allocate an integer number of time slots to each channel. So when at least one channel does not desire an integer number of time slots, then the disclosed embodiments allocate a number of time slots equal to the integer portion to each channel, rolling any fractional remainder over to the next cycle. This cumulative cyclical fractional summing process efficiently allocates time slots among the channels, allowing the average allocation per cycle to approach the true non-integer desired amount over time.

Abstract: A method includes receiving traffic through a first interface in a first group of interfaces at a switch. The first group of interfaces is associated with a first virtual network. The method also includes determining that the traffic is destined for a destination associated with a second virtual network and forwarding the traffic to a second interface in a second group of interfaces at the switch. The second group of interfaces is associated with the second virtual network. The method further includes filtering the traffic that is received at the second interface in the second group of interfaces and communicating the filtered traffic towards the destination. The first and second virtual networks could represent Virtual Local Area Networks associated with different network levels of a process control system.

Abstract: A scheduler and method for scheduling packet forwarding operations is provided. Packet forwarding request information associated with a first set of input port/output port combinations is received. Packet forwarding request information associated with a second set of input port/output port combinations different from the first set of input port/output port combinations is received, where the first set of input port/output port combinations and the second set of input port/output port combinations are selected to not conflict with each other. Packet forwarding for both the first set of input port/output port combinations at a first future time slot and the second set of input port/output port combinations at a second future time slot are simultaneously scheduling at a first scheduler and a second scheduler, respectively, based on the received packet forwarding request information.

Abstract: A system is provided for the controlling the transmission of best-effort filed data or programs on channels from one of plural controllers to one or more client nodes. A program is a group of files and has program information indicating to a client node how to use the files of the program. A channel is a virtual path, wherein a client node can receive program files from different channels in a separate fashion. Channels also have channel information. Multiple controllers are provided which self configure in rank order to control the schedule transmission of programs files on channels. Client nodes receive announcements of programs and channels from the controllers and selectively subscribe to the channels and programs. Client nodes can be instructed to positively acknowledge receipt of programs and also send back negative acknowledgements for ranges of data words in a program files not received. The negative acknowledgements can be consolidated to reduce the number of packets on the network.

Abstract: A process for transmitting asynchronous data packets includes a step of starting a packeting operation. After receiving a message from a message composition module, the process interrupts the packeting operation based on the message. A packet formed during the packeting operation prior to the interrupting step is transmitted. The steps are repeated so as to transmit a plurality of packets.

Abstract: A hierarchical traffic management system and method (i.e., a QoS behavioral model) are disclosed herein. The system includes a classifier operable to identify and classify incoming traffic streams and a queuing system. The queuing system includes a plurality of queues and is operable to apply scheduling policies to the traffic streams. The queues of the queuing system each include enqueue attributes configured to control a depth of the queue and dequeue attributes configured to control scheduling of the queue. The dequeue attributes include minimum bandwidth, maximum bandwidth, excess bandwidth, and priority, wherein each of the queues has one or more of the dequeue attributes defined.

Abstract: To reduce the load on a host for controlling a data doubling. Between a host and two disk subsystems, there is connected a data doubling device. This data doubling device behaves as if it were a unit disk subsystem for the host. The data doubling device doubles a data I/O instruction from the host and issues the doubled data I/O instruction to two disk subsystems. In case either of the disk subsystems becomes faulty, the data doubling device sends the data I/O instruction from the host only to the normal disk subsystem. After the fault recovery, the data doubling device performs a data copy between the disk subsystems.

Abstract: A method and system for an adaptive wireless routing protocol in a mesh network are disclosed. In one embodiment, the method comprises routing datagrams between a plurality of nodes in a mesh network. Update messages are routed to one or more of the plurality of nodes, wherein the update messages include hello packets and update packets.

Abstract: A buffer management system for a data processing system can include a plurality of tokens wherein each token is associated with one of a plurality of buffers, and a plurality of first-in-first-out (FIFO) memories. Each FIFO memory can be associated with a stage of the data processing system and is configured to store at least one of the tokens. The buffer management system also can include control logic configured to determine a state of one or more selected buffers and transfer the token associated with the selected buffer from a source FIFO memory to a target FIFO memory. The target FIFO memory can be selected according to the state of the selected buffer.

Abstract: There are disclosed a method and apparatus for reordering sequenced data packets. An expiration time is calculated for each received data packet. The expiration time and a packet sequence number are stored in a table. The table is read to determine the next data packet to be transmitted in sequence number order. The next data packet is output if available. If the next data packet is not available, a true expiration time is determined for the unavailable next data packet. If the unavailable next data packet fails to arrive before a current time is greater than the expiration time of the unavailable data packet, the unavailable next data packet is considered lost.

Abstract: In packet-oriented data streams, structural information which is needed, for example, for searching or for forwarding or reversing is contained only in specific packets. According to the invention, while a data stream is being stored, an information file is produced which contains references to the starts of all those packets which contain this information. The information file contains data blocks, and each data block identifies the position of a data packet with structural information, as well as the distance to the next or previous such data packet, and additional information relating to the respective data packet.