Abstract: The present invention is directed toward a method and system for maintaining a high quality teleconference. The system provides a way of allowing participants of a conference call to experience the call according to the highest quality codec that their endpoint supports.

Abstract: The present invention is directed to a voice activity detector that uses the periodicity of amplitude peaks and valleys to identify signals of substantially fixed power or having periodicity.

Abstract: The present invention is directed to protecting media packet processors from rogue or malicious data packet flows. According to the present invention, feedback obtained from components of a media packet processor having information regarding media stream flows is used to adjust a counter or token bucket controlling the admission of such flows. More specifically, feedback is used to adjust a counter value such that the count value is decremented, or the operation of the counter in incrementing the count value according to a periodic schedule is suppressed, if a dropped packet is detected. Accordingly, the present invention may utilize the predictable quality of media stream flows, and information from components such as jitter buffers and CODECs, in order to tailor bounds on the flow of ingress traffic to a media packet processor.

Abstract: Clock correlation can be achieved, for example, utilizing the RTP stream between a sender and receiver by determining a baseline at the start of, for example, a communication. This baseline is derived as a point in time from an arriving packet and represents a point from which subsequent packets deviate. Using this baseline, an early packet or a late packet can be detected. An early packet pushes the baseline down to that earlier point, while late arriving packets, if they are arriving late for a continuous period of time, represents a shift in the opposite direction from the baseline, resulting in a baseline moving to the “earliest” packet out of the sequence of the late arriving packets.

Abstract: The present invention is directed, in various embodiments, to a hardware supported duplication token for arbitrating active and standby module states, a weighted state of health exchange for identifying unhealthy module states and relative module health states, and a packet sequence number synchronization technique for maintaining desired levels of synchronization between the active and standby modules.

Abstract: A location-based reminder system includes a controller 112 that determines when a person is in and/or leaving a defined area 104; when a person is determined to be in and/or leaving the defined area 104, identify a reminder to be provided to the person, the reminder including information about at least one object associated with the person; and provide the reminder to the person before the person leaves the defined area 104.

Abstract: Clock correlation can be achieved, for example, utilizing the RTP stream between a sender and receiver by determining a baseline at the start of, for example, a communication. This baseline is derived as a point in time from an arriving packet and represents a point from which subsequent packets deviate. Using this baseline, an early packet or a late packet can be detected. An early packet pushes the baseline down to that earlier point, while late arriving packets, if they are arriving late for a continuous period of time, represents a shift in the opposite direction from the baseline, resulting in a baseline moving to the “earliest” packet out of the sequence of the late arriving packets.

Abstract: Techniques are disclosed for establishing packet-based communication between first and second endpoints over a network, in a manner which reduces the latency and complexity associated with call setup. In accordance with one aspect of the invention, a resource is requested from the network utilizing a first protocol, and while the request is pending, transmission of packets at a first priority level is commenced. After a response is received from the network granting access to the requested resource, a tagging mechanism is utilized to identify particular packets for transmission at a second priority level higher than the first priority level. In an illustrative embodiment, the first protocol is the Resource Reservation Protocol (RSVP), the first priority level corresponds to a Better than Best Effort (BBE) policy, and the second, higher priority level corresponds to an Expedited Forwarding (EF) policy.

Abstract: The present invention is directed to a voice activity detector that uses the periodicity of amplitude peaks and valleys to identify signals of substantially fixed power or having periodicity.

Abstract: A system for determining a topology associated with a network such as an enterprise network. The system includes a data collection agent 204 configured to (a) identify a first set of routers from among a larger, second set of routers in an enterprise network, (b) contact each of the routers in the first set of routers but not each of the other routers in the second set of routers, and (c) load network information maintained by at least some of the contacted routers in the first set of routers. The loaded network information can then be used to form a network or routing topology of the enterprise network.

Abstract: Synchronization of related packet data network streams is provided. Synchronization is achieved by inserting synchronization packets into data streams that are to be aligned with one another after transmission of those data streams across a network. More particularly, corresponding synchronization packets are inserted into the corresponding data streams at the same time, to serve as markers for performing synchronization of the data at the receiving end. The corresponding data streams may comprise an audio data stream and a corresponding video data stream.

Abstract: A double-talk detector (109) for an acoustic echo canceler (104) of a VoIP terminal (101) converts (216,226) received far-end signals (212) and transmitted near-end signals (222) into the frequency domain and high-pass filters out (218,228) low-frequencies representing noise to obtain a complex reference signal and a complex error signal, respectively. It then correlates (230) the complex signals and computes (232) the instantaneous error energy (234) and smoothed (long-term average) error energy (235) of the complex error signal. If the convergence value is below 0.06 (300), the signals are converged and double-talk detection is enabled (306). If the convergence value is above 0.09 (312), the signals are diverged and double-talk detection is disabled (316). If double-talk detection is not enabled, an error threshold (236) is set (304,318) to the value of the smoothed error energy.

Abstract: Techniques are disclosed for establishing packet-based communication between first and second endpoints over a network, in a manner which reduces the latency and complexity associated with call setup. In accordance with one aspect of the invention, a resource is requested from the network utilizing a first protocol, and while the request is pending, transmission of packets at a first priority level is commenced. After a response is received from the network granting access to the requested resource, a tagging mechanism is utilized to identify particular packets for transmission at a second priority level higher than the first priority level. In an illustrative embodiment, the first protocol is the Resource Reservation Protocol (RSVP), the first priority level corresponds to a Better than Best Effort (BBE) policy, and the second, higher priority level corresponds to an Expedited Forwarding (EF) policy.

Abstract: A system for determining a topology associated with a network such as an enterprise network. The system includes a data collection agent 204 configured to (a) identify a first set of routers from among a larger, second set of routers in an enterprise network, (b) contact each of the routers in the first set of routers but not each of the other routers in the second set of routers, and (c) load network information maintained by at least some of the contacted routers in the first set of routers. The loaded network information can then be used to form a network or routing topology of the enterprise network.

Abstract: A double-talk detector (109) for an acoustic echo canceler (104) of a VoIP terminal (101) converts (216,226) received far-end signals (212) and transmitted near-end signals (222) into the frequency domain and high-pass filters out (218,228) low-frequencies representing noise to obtain a complex reference signal and a complex error signal, respectively. It then correlates (230) the complex signals and computes (232) the instantaneous error energy (234) and smoothed (long-term average) error energy (235) of the complex error signal. If the convergence value is below 0.06 (300), the signals are converged and double-talk detection is enabled (306). If the convergence value is above 0.09 (312), the signals are diverged and double-talk detection is disabled (316). If double-talk detection is not enabled, an error threshold (236) is set (304,318) to the value of the smoothed error energy.

Abstract: A voice-activity detector (VAD 104) takes (214) a currently-received set and a previously-received set of samples of a time-domain (voice) signal, converts (216) them into a frequency-domain representation of the signal, filters out (218) negative and low (noise) frequencies, weights (220) the energies of frequency bins (ranges) of the remaining frequencies proportionately to their frequencies, and computes (220) the total power of the ranges. It first initializes (226) by determining (304, 306) if power peaks of any of the ranges exceed a first threshold (ceiling 228); if not, it lowers (302) the ceiling and continues initializing, and if so, it ends initializing (308), indicates (334) that voice has been detected, sets (330) the ceiling to the highest peak, and stores (332) the total power as a “smoothed” power.