At&t Intellectual Property I, LP

At+t Corp.

At&t Bell Laboratories

American Telephone and Telegraph, Co.

Robert G Cole

Gagan Choudhury

Howard Lang

Joshua Hal Rosenbluth

Manoel A Rodrigues

Eric M Woerner

Kerry W Fendick

Howard L Lang

James M Amster

Eric Woerner

The present invention relates to an apparatus and method for maintaining voice call quality over a packet network by providing optimal de-jitter buffer depth and rate of change of depth. Buffer depth and rate of change of buffer depth may be initially determined by classifying the incoming call. Classification of the incoming calls may be accomplished by categorizing calls into groups based on characteristics of the calls. The buffer depth and rate of change of depth may be further optimized at the start of calls based on voice-path delay and packet loss probability measurements over one or more calls of the same class such that the voice-path delay is minimized while maintaining a certain packet loss probability, the packet loss probability is minimized while maintaining a certain voice-path delay, or an R-factor, which is an objective measure of voice quality, is maximized.

Method and apparatus for managing voice call quality over packet networks

A system and method make quality measurements in a network to determine if a Service Level Agreement is breached. The system includes a plurality of routers for routing traffic through the network, means for taking measurements on a path between a first router and a second router, and means for charging at least one of the plurality of routers when data related to the measurements falls below a target value.

Method for determining VoIP gateway performance and SLAs based upon path measurements

The quality of conversational voice for Voice-over-Packet transmissions on a Path () in a packet network () is achieved by injecting probe packets for transmission along the path and then measuring packet loss and the delay. From the delay and loss measurements, analytic values for the voice quality impairment caused by delay and by network loss, respectively, are established. An overall measure of the conversational voice quality is then derived in accordance with the algebraic sum of the analytic values for the voice quality impairment caused by delay and by network loss, respectively.

Technique for monitoring conversational voice over packet

Congestion control is implemented at the resources that actually suffer from congestion and, moreover the congestion control is performed within the network as well as at its access points. In a particular embodiment, congestion control is continuously performed at each resource. Use of each resource is controlled according to a head-of-the-line weighted round-robin service discipline thereby assuring fairness and full use of bandwidth for all active channels. Also, in order to control conditions of congestion, the queue of data elements waiting for service at each resource is regulated by a global congestion indicator for the entire queue. The data elements of each channel that are waiting for service are further regulated in response to specific local congestion indicators that are individualized for each channel. The global and local congestion indicators are used to guarantee predetermined levels of service for each channel. The values employed for the head-of-the-line weighted round-robin service discipline are developed as a function of at least the contracted-for bandwidth for each channel. The developed values are replicated for each resource subject to congestion control.

Service guarantees/congestion control in high speed networks

Growing community of inventors

Churchville, MD, United States of America

Robert G Cole