Abstract: A system and method for reconstructing a service clock between two, first and second subsystems communicating therebetween, comprising a first subsystem operative to generate first subsystem timestamps, a second subsystem operative to generate second subsystem timestamps at a second frequency different from the first timestamps, wherein the generations of both first and second timestamps are based on sampling of the service clock by a common clock available at both subsystems, and an aligner for arithmetically aligning the different first and second subsystem timestamps to reconstruct the service clock.

Abstract: A method and apparatus are provided for optimizing retrieval of network resources. In one embodiment, a method of optimizing access to a network resource is implemented in a computer program executed by a router, cache server, or proxy server. A network resource that contains one or more embedded symbolic host name references is received. A network address corresponding to each of the embedded symbolic host name references is determined. A modified copy of the network resource is created and stored; in the modified copy, a network address is substituted for each corresponding embedded symbolic host name reference. Thereafter, the modified copy of the network resource in responding to all subsequent client requests for the network resource, thereby greatly reducing the required number of network address lookup operations. In one specific embodiment, IP addresses are determined using DNS queries for the hostname portion of all URLs that are embedded in a Web page using image, applet, object, or embed tags.

Abstract: A method of automatically establishing differentiated services quality of service treatment for a return packet flow that is associated with an originating packet flow in a network is disclosed. The originating packet flow is received, and it is determined that one or more packets in the originating packet flow are marked with a DSCP value that matches a policy rule that instruct setting of a specified DSCP value to the return packet flow. In response, information identifying the originating packet flow and a second DSCP value for marking the return packet flow is created and stored. When a corresponding return packet flow is received and determined to be associated with the originating packet flow, packets of the return packet flow are automatically marked with the second DSCP value. Once the packet flow terminates, all stored information is removed.

Abstract: A method, apparatus, and computer-readable medium configured for maintaining consistent per-hop packet forwarding behavior among a plurality of network devices in a network within a Differentiated Services (DS) domain are disclosed. In one aspect, a method involves creating and storing a network-wide PHB definition that associates a PHB with a DS code point (DSCP) value, and with a set of parameters that define the bandwidth and buffer resources allocated to the PHBs on all interfaces of network devices within the DS domain. A mapping of each of the PHBs in the network-wide PHB definition to one or more queues of the network devices is determined. Drain size and queue size values are determined for each of the queues to which PHBs are mapped. A mapping of each of the PHBs to a threshold value associated with the queues is determined. Parameters of fragmentation and interleave mechanisms are determined.

Abstract: A pharmaceutical composition which comprises a therapeutically effective amount of a aminopyridine dispersed in a release matrix, including, for example, a composition that can be formulated into a stable, sustained-release oral dosage formulation, such as a tablet which provides, upon administration to a patient, a therapeutically effective plasma level of the aminopyridine for a period of at about 12 hours and the use of the composition to treat various neurological diseases, including multiple sclerosis. A method of selecting individuals based on responsiveness to a treatment, including, for example, identifying individuals who responded to treatment with a sustained release fampridine composition.

Abstract: A novel and useful apparatus for and method of determining the channel order and channel estimate in a communications system such as a wireless communication system including cellular and cordless. Such channels are typically characterized by rapidly changing impulse response and their taps can be modeled as zero-mean, complex, Gaussian random processes. A sufficiently long, initial channel estimate of length is performed so as to ensure that the actual channel taps will be contained in the estimated taps thus making certain that the equalizer will effectively eliminate intersymbol interference. Channel estimation is performed during each burst using the training sequence transmitted in the middle of the burst. The tap energies are averaged so as to track slow variations in the pattern of resultant channel taps. A noise floor is calculated using the lowest averaged taps and a threshold is computed based thereon and applied to the average taps.

Abstract: A method for replacing lost or delayed data in SONET/SDH emulation protocols for carrying signals over a packet network between a sender and a receiver. The method comprises receiving a plurality of packets, each said packet having packet parameters, detecting a missing packet and instead of the missing packet, playing out a replacement packet that includes replacement values chosen to minimize erroneous stuffing events. The replacement values are determined based on packet information tracked by the receiver (102), and optionally on statistics maintained by the receiver and on information tracked by the sender (100).

Abstract: A method, apparatus, and computer-readable medium configured for maintaining consistent per-hop packet forwarding behavior among a plurality of network devices in a network within a Differentiated Services (DS) domain are disclosed. In one aspect, a method involves creating and storing a network-wide PHB definition that associates a PHB with a DS code point (DSCP) value, and with a set of parameters that define the bandwidth and buffer resources allocated to the PHBs on all interfaces of network devices within the DS domain. A mapping of each of the PHBs in the network-wide PHB definition to one or more queues of the network devices is determined. Drain size and queue size values are determined for each of the queues to which PHBs are mapped. A mapping of each of the PHBs to a threshold value associated with the queues is determined. Parameters of fragmentation and interleave mechanisms are determined.

Abstract: A method, apparatus, and computer-readable medium configured for maintaining consistent per-hop packet forwarding behavior among a plurality of network devices in a network within a Differentiated Services (DS) domain are disclosed. In one aspect, a method involves creating and storing a network-wide PHB definition that associates a PHB with a DS code point (DSCP) value, and with a set of parameters that define the bandwidth and buffer resources allocated to the PHBs on all interfaces of network devices within the DS domain. A mapping of each of the PHBs in the network-wide PHB definition to one or more queues of the network devices is determined. Drain size and queue size values are determined for each of the queues to which PHBs are mapped. A mapping of each of the PHBs to a threshold value associated with the queues is determined. Parameters of fragmentation and interleave mechanisms are determined.

Abstract: An adaptive rate management method and system for adapting a receiver rate to a transmission rate in a packet switch network comprises determining an error value at a sample rate, obtaining an updated accumulator value based on said error value Es at a decimated sample rate, and generating an appropriate rate command and changing said accumulator value at the decimated rate based on the updated accumulator value. The method may be adapted for either adapter point management or bit stuffing. When applied to adapter point management (APM), the method generates pointer adjustments for rate management. In a frequency locked APM preferred embodiment of the method and system, pointer adjustments in an interval are generated at a constant rate based on an average pointer adjustment value calculated in previous intervals.

Abstract: A method for calculating jitter buffer depth in a packet switching network comprises receiving at a receiver N pairs of identical packets sized S1 and S2, sent by a sender with a known time interval between them, measuring an arrival time interval for each pair, calculating a speed factor using an average of the arrival time intervals and calculating the jitter buffer depth using the speed factor and the packet sizes. An optimized packetization delay at a sender can be then calculated using the jitter buffer depth.

Abstract: An architecture and method for enhancing a TDM cross-connect to perform packet switching. In particular, a method and architecture that adds to an existing TDM switch at least two packet switching line cards that perform all packet-processing tasks includind filtering, shaping and policing, forwarding and scheduling, while utilizing the TDM cross-connect existing infrastructure.

Abstract: A method for compressing a packetized SONET/SDH stream for transmission over a packet switched network, comprising identifying a C2 byte in the stream, and, based on the identification, applying a C2 byte-related compression algorithm to compress the stream. The C2 byte is either extracted by a packet processor from a packet payload or header, pre-configures within an ingress packetizer, or identified automatically from examining the SONET circuit sent from an egress packetizer back to an ingress packetizer. Various embodiments of the compression algorithms include algorithms based on identifications of unequipped C2=0x0, virtual tributaries C2=0x02, HDLC C2=0x16, PPP C2=0xCF, and asynchronous DS-3 C2=0X04.

Abstract: The present invention discloses a novel scheme of performing frequency domain filtering that does not require a Hilbert transform and which is faster than equivalent FIR filtering schemes. Such a scheme has applications in implementing filters in voice band modems on OSP platforms and in numerous other applications as well. The scheme of the present invention is shown to be superior in term of CPU resource consumption and memory storage space when compared with an equivalent implementation using prior art time domain convolution techniques. The scheme of the present invention permits the delay buffer in the far end echo canceler to store the signal in real format rather than complex format, thus reducing memory requirements by half. The present invention implements a real to analytic fast convolution in the frequency domain which uses zero CPU resources.

Abstract: The present invention discloses a novel scheme of performing frequency domain filtering that does not require a Hilbert transform and which is faster than equivalent FIR filtering schemes. Such a scheme has applications in implementing filters in voice band modems on OSP platforms and in numerous other applications as well. The scheme of the present invention is shown to be superior in term of CPU resource consumption and memory storage space when compared with an equivalent implementation using prior art time domain convolution techniques. The scheme of the present invention permits the delay buffer in the far end echo canceler to store the signal in real format rather than complex format, thus reducing memory requirements by half. The present invention implements a real to analytic fast convolution in the frequency domain which uses zero CPU resources.

Abstract: An apparatus for and method of implementing a novel buffer based full duplex communication system is disclosed. The disclosed invention is particularly useful in native signal processing systems wherein heavy contention of processor resources typically exist, such as in systems running multi-tasking operating systems. The communication system of the present invention includes a receiver, transmitter, echo canceler, CODEC and telephone hybrid. The major components of the system operate on a buffer of input samples consisting of a set of input bits. The communication system operates to generate a buffer of output samples consisting of a set of output bits. The invention utilizes a novel buffer switching mechanism to optimize the tradeoff between processing response time, on one hand, and robustness to interrupt latency and processor implementation on the other hand.

Abstract: A method for routing messages within a LAN between a first station attached to the LAN and belonging to a first network and a second station attached to the LAN and belonging to a second network, the method including providing a router operatively attached to both the first network and the second network, sending a frame from the first station to the router, the frame including a destination address of the second station, and sending a redirect message from the router to the first station, the redirect message including a pool address associated with the second station.

Abstract: A novel system by which the utilization of a central processing unit (CPU) in performing filtering operations can be reduced by shortening the filter's length thus degrading the performance of the system down to a predetermined level or threshold. The present invention is applicable to such systems that incorporate filters whereby shortening their length decreases the performance of the system and to such systems where a reliable quality criteria exists that can be measured during run time. A method iteratively minimizes the filter's length so that the quality criteria does not fall below a predetemined threshold level. In addition, a signal to noise ratio (SN) criteria is suggested for estimating the quality of the reception of communication signals. An implementation is suggested for the method in the particular case of an echo cancellation adaptive filter. In addition, a method for determining an immediate approximation of the echo canceler filter's length as opposed to finding it iteratively.

Abstract: An apparatus for and method of implementing a novel buffer based fall duplex communication system is disclosed. The disclosed invention is particularly useful in native signal processing systems wherein heavy contention of processor resources typically exist, such as in systems running multi-tasking operating systems. The communication system of the present invention includes a receiver, transmitter, CODEC and telephone hybrid. The major components of the system operate on a buffer of input samples consisting of a set of input bits. The communication system operates to generate a buffer of output samples consisting of a set of output bits. The invention utilizes a novel dynamic buffer size mechanism to optimize the tradeoff between buffer delay and processing time period, on one hand, and robustness to interrupt latency and processor availability on the other hand. Small buffers provide the communication system with short, accurate response times in addition to short processing times.

Abstract: An apparatus for and method of implementing a novel buffer ba full duplex communication system is disclosed. The disclosed invention is particularly useful in native sign processing systems wherein heavy contention of processor resources typically exist, such as in systems running multi-tasking operating systems. The communication system of the present invention includes a receiver, transmitter, echo canceler. CODEC and telephone hybrid. The major components of the system operate on a buffer of input samples consisting of a set of input bits. The communications system operates to generate a buffer of output samples consisting of a set of output bits. The invention utilizes a novel buffer switching mechanism to optimize the tradeoff between processing response time, on one hand, and robustness to interrupt latency and processor implementation on the other hand.