Abstract: In one embodiment, a method includes (a) discerning whether an average packet delay in a media streaming session is increasing or decreasing over a first defined time window, (b) discerning whether an average jitter in the media streaming session is increasing or decreasing over a second defined time window, (c) in response to (a) and (b), calculating a specific bit-rate quantity corresponding to a change in bit-rate, and (d) controlling a bit-rate of the media streaming session in accordance with the specific bit-rate quantity.

Abstract: Techniques are presented herein for a multicast server to group receivers, or user devices, with other receivers having similar characteristics, so that the group can be paired with source-specific multicast channel that is optimized specifically for the receivers of the group. The server receives information regarding hardware and network capabilities from each of the user devices. The server then groups the user devices according to their information, where each group contains user devices having hardware and network information that is similar to one another. The server then receives, at random intervals, network reports that are generated by at least one user device from at least one of the groups, where the network reports include information related to the network performance experienced by a user device. The server then adjusts the SSM channel associated with the group of user devices based on the information in the network report.

Abstract: A scalable media conferencing system minimizes delay while maintaining a consistent session across all of the distributed media servers handling the conference session. Each of the media servers sends a list of the local top streams and their importance. A global list of top streams is created and disseminated to all of the media servers. Each of the media servers then forwards any local stream that is on the list of global top streams to all of the other media servers. Once a media server receives all of the streams on the list of global top streams, it locally mixes the streams together and outputs the mixed stream to the endpoints that are locally connected to that media server.

Abstract: Techniques are presented herein for a multicast server to group receivers, or user devices, with other receivers having similar characteristics, so that the group can be paired with source-specific multicast channel that is optimized specifically for the receivers of the group. The server receives information regarding hardware and network capabilities from each of the user devices. The server then groups the user devices according to their information, where each group contains user devices having hardware and network information that is similar to one another. The server then receives, at random intervals, network reports that are generated by at least one user device from at least one of the groups, where the network reports include information related to the network performance experienced by a user device. The server then adjusts the SSM channel associated with the group of user devices based on the information in the network report.

Abstract: Techniques are provided for managing network traffic and alleviating network congestion issues in video conference environments. At a video conference bridge device configured to send and receive communications to an endpoint device in a network, one or more video streams are received from the endpoint participating in a video conference. Each of the video streams is classified as a rate adaptive stream or as a non-rate adaptive stream. For video streams classified as rate adaptive streams, the video streams are assigned to a buffer queue for rate adaptive streams. For video streams classified as non-rate adaptive streams, the video streams are assigned to a buffer queue for non-rate adaptive streams.

Abstract: In one embodiment, an apparatus includes two modules. A first module receives a request from a first endpoint to subscribe to a voice activated multicast group and causes the first endpoint to receive a current speaker's video stream if the first endpoint is not the current speaker and to receive a last speaker's video stream if the first endpoint is the current speaker. A second module receives a request from a second endpoint to subscribe to a continuous presence multicast group and causes the second endpoint to receive a continuous presence, current speaker video stream if the second endpoint is not the current speaker and to receive a continuous presence, last speaker video stream if the second endpoint is the current speaker. The continuous presence, current speaker video stream includes a composition or two or more video streams, one of which includes at least a portion of the current speaker's video stream.

Abstract: A scalable media conferencing system minimizes delay while maintaining a consistent session across all of the distributed media servers handling the conference session. Each of the media servers sends a list of the local top streams and their importance. A global list of top streams is created and disseminated to all of the media servers. Each of the media servers then forwards any local stream that is on the list of global top streams to all of the other media servers. Once a media server receives all of the streams on the list of global top streams, it locally mixes the streams together and outputs the mixed stream to the endpoints that are locally connected to that media server.

Abstract: An apparatus may receive a plurality of data streams for transmission over a network. The apparatus may adjust packet drop rates in proportion to differences between actual bit rates and target bit rates of the data streams. Information about the adjusted packet drop rates may be provided to rate adaptive endpoints that are generating the data streams. The rate adaptive endpoints may respond to the information by adjusting the bit rates at which the data streams are encoded. Over one or more time intervals, the bit rates are adjusted to levels that yield a transmission of the data streams that is both balanced and unbiased.

Abstract: Techniques are provided for managing network traffic and alleviating network congestion issues in video conference environments. At a video conference bridge device configured to send and receive communications to an endpoint device in a network, one or more video streams are received from the endpoint participating in a video conference. Each of the video streams is classified as a rate adaptive stream or as a non-rate adaptive stream. For video streams classified as rate adaptive streams, the video streams are assigned to a buffer queue for rate adaptive streams. For video streams classified as non-rate adaptive streams, the video streams are assigned to a buffer queue for non-rate adaptive streams.

Abstract: In one embodiment, a method includes receiving application traffic at a network device from one or more endpoints, measuring performance of applications at the network device, optimizing TCP (Transmission Control Protocol) applications and UDP (User Datagram Protocol) applications based on the measured performance and policy input received at the network device, queuing the application traffic at the network device such that the application traffic shares available bandwidth in accordance with the measured performance and the policy input, and transmitting the application traffic over a wide area network. An apparatus is also disclosed.

Abstract: An apparatus and methods are provided for shaping a transmit bit-rate of a multimedia stream to adapt to the bandwidth of network path on which the multimedia stream is sent between a source and destination. A condition indicative of a bandwidth of the network path is monitored, and at an intermediate point on the network path between the source and destination, the transmit bit-rate of the multimedia stream is adjusted to adapt to the condition indicative of the bandwidth of the path.

Abstract: A rate adaptive video conference bridge and related techniques are provided. At a video conference bridge, a source video stream is received from a source endpoint device in a network. The source video stream is encoded using a first encoder unit and second encoder unit to generate respective first and second encoded video streams. A determination is made whether to decrease or increase a bit rate of the source video stream based on network condition information. If the bit rate is to be decreased, the first encoder unit is instructed to send the first encoded video stream to a destination endpoint device. If the bit rate is to be increased, the second encoder unit is instructed to send the second encoded video stream to the destination endpoint device.

Abstract: An apparatus may receive a plurality of data streams for transmission over a network. The apparatus may adjust packet drop rates in proportion to differences between actual bit rates and target bit rates of the data streams. Information about the adjusted packet drop rates may be provided to rate adaptive endpoints that are generating the data streams. The rate adaptive endpoints may respond to the information by adjusting the bit rates at which the data streams are encoded. Over one or more time intervals, the bit rates are adjusted to levels that yield a transmission of the data streams that is both balanced and unbiased.

Abstract: Disclosed are video conferencing systems, devices, architectures, and methods for transcoding, transrating, and the like, to facilitate video streaming in a distributed arrangement. An exemplary translator in accordance with embodiments can include: an input configured to receive a first video stream in a first format, the first video stream being from a first media switch, the first media switch being associated with a first stream group having one or more first endpoints; and an output configured to provide a second video stream in a second format, the second video stream being sent to a second media switch, the second media switch being associated with a second stream group having one or more second endpoints, whereby the translator is configured to convert from the first to the second format.

Abstract: In one embodiment, an apparatus includes two modules. A first module receives a request from a first endpoint to subscribe to a voice activated multicast group and causes the first endpoint to receive a current speaker's video stream if the first endpoint is not the current speaker and to receive a last speaker's video stream if the first endpoint is the current speaker. A second module receives a request from a second endpoint to subscribe to a continuous presence multicast group and causes the second endpoint to receive a continuous presence, current speaker video stream if the second endpoint is not the current speaker and to receive a continuous presence, last speaker video stream if the second endpoint is the current speaker. The continuous presence, current speaker video stream includes a composition or two or more video streams, one of which includes at least a portion of the current speaker's video stream.

Abstract: Techniques are provided for sending and receiving key frames and key frame request messages. At a video conference bridge, a key frame request message is received from a first endpoint device. The key frame request message comprises a request for a key frame from a second endpoint device. When a prior key frame request message is received before the key frame request message, a key frame request time value is determined that corresponds to an amount of time between receiving the key frame request message and receiving the prior key frame request message. This value is compared to a threshold time value. When the key frame request time is greater than the threshold time, a key frame request forwarding message is generated, and the key frame request forwarding message is sent to the second endpoint device to request the key frame from the second endpoint device.

Abstract: A method for executing a video conference is provided that includes receiving one or more audio streams associated with a video conference from one or more end points and determining an active speaker associated with one of the end points. Audio information associated with the active speaker may be received at one or more media switches. One or more video streams may be suppressed except for a selected video stream associated with the active speaker, the selected video stream propagating to one or more of the media switches during the video conference. The selected video stream may be replicated such that it may be communicated to one or more of the end points associated with a selected one of the media switches.

Abstract: In one embodiment, a method can include: (i) establishing an internet protocol (IP) connection; (ii) forming a buffered version of a plurality of voice frame slices from received audio packets; and (iii) when an erasure is detected, performing a packet loss concealment (PLC) to provide a synthesized speech signal for the erasure, where the PLC can include: (a) identifying first and second pitches from the buffered version of the plurality of voice frame slices; and (b) forming the synthesized speech signal by using the first and second pitches, and more if needed, followed by an overlay-add (OLA).

Abstract: In one embodiment, an apparatus includes a first module that causes the first endpoint to receive a current speaker's video stream if the first endpoint is not the current speaker and to receive a last speaker's video stream if the first endpoint is the current speaker. The apparatus includes a second module that causes the second endpoint to receive a continuous presence, current speaker video stream if the second endpoint is not the current speaker and to receive a continuous presence, last speaker video stream if the second endpoint is the current speaker. The continuous presence, current speaker video stream comprises two or more video streams, one of which includes at least a portion of the current speaker's video stream. The continuous presence, last speaker video stream comprises two or more video streams, one of which includes at least a portion of a last speaker's video stream.

Abstract: According to an embodiment of the present invention, an apparatus for performing video conferencing is provided that includes an I-frame injector element operable to intercept I-frame requests from one or more end points and to attempt to service the I-frame requests such that at least a portion of the requests are prevented from propagating back to an originating sender. In more specific embodiments, when a receiver endpoint sends a fast video update (FVU) request upstream, it is intercepted by the I-frame injector element and rather than passing the FVU request to the sender the I-frame injector element replaces a next P-frame from the sender with an I-frame, whereby the I-frame is constructed so that when decoded, it matches the P-frame that it replaced. In still more detailed embodiments, the I-frame injector element operates in one of three modes that are associated with bandwidth parameters.