Verizon Laboratories Inc.

Cisco Technology, Inc.

Cisco Systems Inc.

Liehua Xie

Gonzalo R Arce

Evert Basch

Arianne Michelle Lewis

Choon B Shim

Peter Flynn

This method and apparatus is used to process call control protocol messages and quality of service media streams from an internet protocol conferencing session. The status and attributes processed from call control protocol messages are combined with the quality of service information for the parties connecting to a conferencing session for display to users in real-time.

Method and apparatus for voice conference monitoring

The invention relates to a system and method for load-balancing multiple servers in a communications network. Instead of using round robin or other predetermined scheme, SIP messages are forwarded to one of multiple SIP servers according to a performance score that is calculated from measured performance data. Advantageously, the disclosed system and method decreases signaling latency, improving overall communications speed. Moreover, where performance data indicates that a SIP server has failed, the performance score for the failed SIP server is zero, and the load balancer will not forward SIP messages to the failed SIP server. System uptime is also improved.

System and method for load balancing a communications network

A method of generating a authentication code (&ldquo;MAC&rdquo;) with improved error tolerance exhibits improved survivability against acceptable signal distortions such as recompression. A method of generating a message authentication code associated with an image includes receiving blocks of image coefficient data where each coefficient has an original value falling within a range of values. The range of values is divided into first and second regions both having allowed coefficient values, and an error tolerance buffer region formed between the first and second regions having disallowed coefficient values. The original values of DC coefficients from each block of the image coefficient data is mapped to a modified value contained in one of the first and second regions, but not contained in the error tolerance buffer region. A MAC is generated as a function of the most significant bits of the modified image coefficient values.

Message authentication code with improved error tolerance

According to the principles of the invention, there is provided a system for generating a message authentication code for a conventional digital video stream. The system operates on the rows and columns of block data for a video stream, and more specifically on histograms of DC coefficients from each row and column, to produce a compact code that is nonetheless descriptive of the underlying images in the video stream. The message authentication code can be reproduced from the images of a received video stream, and if desired, compared with a digital watermark embedded in the video stream in order to confirm the accuracy of the video content or identify the source of the video stream.

Message authentication code using image histograms

A system ( ) for watermarking digital data includes a watermark etching subsystem ( ) and a watermark extraction subsystem ( ). The watermark etching subsystem ( ) obtains a matrix of digital data values, selects windows including a plurality of data values from the matrix, specifies a parameter that indicates an acceptable amount of variation in the data values, and etches watermark bits in each window of data values using the specified parameter. The watermark extraction subsystem ( ) obtains a matrix of digital data values containing an etched watermark, selects windows comprising a plurality of data values from the matrix, and extracts watermark bits from each window of data values using the specified parameter.

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Herndon, VA, United States of America

Liehua Xie