Dialogic Corporation

Ulysses Esd, Inc.

Snowshore Networks, Inc.

Andy Spitzer

Eric William Burger

John Jeffrey Van Dyke

Walter Joseph O'Connor

Rongrong Wu

Barry David Wessler

A method and apparatus for terminating a communication session at a first communication device that had established a communication session with a second communication device in response to a determination that the first communication device has not received any media packets from the second communication device within at least one predetermined time period. In the event the first device determines that no media packets have been received from the second device within a first predetermined time period, a probe is sent to the second device. If a positive response is not received by the first device within a second predetermined time period from the sending of the probe, the first device terminates the session. If a positive response is received by the first device in response to the probe, the first device transmits additional probes during the session whenever media packets are not received from the second device within a third predetermined time period and the session is terminated by the first device if a response to the respective probe is not received within the second predetermined time period.

Method and apparatus for detecting stuck calls in a communication session

A conferencing system that can access advanced conferencing features while following essentially the same call flow as conventional conferencing systems. The conferencing system includes a computer network, and at least one conferencing application server, at least one media server, and at least one user agent connected to the network. The conferencing application server establishes and manages multimedia conferences by engaging in Session Initiation Protocol (SIP) signaling with the user agents and the media server. Once the conference is established, the media server generates multimedia data such as audio data and conveys the data to the conference participants. In order to access advanced conferencing features, the conferencing system employs an enhanced SIP signaling technique including a conferencing Application Programming Interface (API) implemented by incorporating Extensible Mark-up Language (XML) messages in the bodies of respective SIP request/response messages. The XML messages are incorporated in the SIP request/response message bodies to convey conference specific commands and/or parameters that cannot be easily described via the Session Description Protocol (SDP).

Conferencing architecture employing media servers and enhanced session initiation protocol

A sample jitter buffer manager more or less aggressively conserves (rations) or discards data in a jitter buffer, based on the fluctuating amount of data in the jitter buffer. The jitter buffer manager counts, provides, discards and/or otherwise manages individual sample data units, rather than entire packets. Normally, enough data is removed from the jitter buffer to fill a data packet for a receiver. However, if the amount of data in the jitter buffer is low, less data is removed from the jitter buffer and placed into the packet, and the remainder of the packet is filled with duplicates of some of the data in the packet or in the jitter buffer. As the jitter buffer fills beyond a useful level, the jitter buffer discards progressively larger amounts of data, without necessarily discarding one or more entire packets. This fine-grained management of the amount of data in the jitter buffer maintains a buffer size that can provide a steady stream of packets to the receiver, without significantly impacting the fidelity of a signal represented by the data, and it mitigates the impact of fluctuations in packet inter-arrival times.

Jitter buffer management

A system and method for constructing phrases for delivery by a media server over a network to a client. Upon initiation of a session an initial ordered play list comprising a plurality of identifiers is conveyed to the media server. Each identifier on the ordered play list is associated with an audio prompt file constituting a prerecorded audio message, an audio component file comprising a component of a variable audio message to be conveyed to the client or a identifier list comprising at least one identifier. Each identifier contains information sufficient to fetch the content associated with the respective identifier from another server. The media server utilizes the first identifier on the ordered play list to fetch the content associated with that identifier from a server specified by the identifier and removes the respective identifier from the ordered play list. The media server then determines whether the retrieved content is an audio file. If the retrieved content comprises an audio file, the file is played to the client. If the file comprises an identifier list, the identifier list is inserted at the top of the current ordered play list and the media server continues to fetch files associated with the respective identifiers on the ordered play list in sequence. This process continues until no more identifiers are present on the ordered play list. Once the play list has been exhausted, the audio message comprising any prompt files and variable data to be played to the client has been communicated over the network.

System and method for constructing phrases for a media server

A method and apparatus for testing a conference server. A plurality of test tone signals are generated. In one embodiment each test tone signal comprises the sum of at least two distinct frequency signals. Each test tone signal is employed to simulate a participant and the test tone signals are applied to a plurality of inputs of the conference server. At least some of the test tone signals are combined by the conference server to produce a corresponding plurality of test output signals. The test output signals are analyzed to identify whether the proper test tone signals are present within the respective test output signals. The generation of test tone signals and the analysis of the conference server outputs may be automated to facilitate rapid testing of conference server functionality. An indication of the test results are generated.

Method for testing large-scale audio conference servers

An embodiment of the invention described in the specification and drawings is a distributed and highly available data storage system. In one embodiment, the distributed data storage system includes a plurality of data storage units that are controlled by an object management system. The object management system preferentially selects the distributed data storage units for performing the file access requests according to the external inputs/outputs with which the file access requests are associated. In response to a file creation request that is associated with an external input of one distributed data storage unit, the object management system preferentially creates a data file in that distributed data storage unit. In response to a file retrieval request that is associated with a data file and an external output of a distributed data storage unit, the object management system preferentially returns a hostname and pathname of a copy of the data file that is stored within that distributed data storage unit. The object management system also makes redundant copies of the data files in different units to provide high availability of data.

Network-based disk redundancy storage system and method

To form communication connections in a set of nodes, the set of nodes is arranged so that at least a subset of the nodes form a ring. Each node in the subset of nodes is coupled to first and second neighboring nodes in the subset by a set of inter-node communication connections. An external communication is received at one of the nodes. The external communication requests access to a communication resource of a specified type. The receiving node determines whether it has an available communication resource of the specified type. If not, the following additional steps are performed. A resource request message is sent to the first and second neighboring nodes of the receiving node to request allocation of a communication resource of the specified type. Each of the first and second neighboring nodes determines whether that node has an available communication resource of the specified type. If not, the neighboring node transmits another resource request message to one of its neighboring nodes other than the node from which the resource request message was received. When any node determines that it has an available communication resource of the specified type, a communications path is formed between the receiving node and the communication resource of the specified type via the inter-node communication connections therebetween.

Growing community of inventors

North Andover, MA, United States of America

Andy Spitzer