Hewlett-packard Company

Agilent Technologies, Inc.

Jeffrey Tomberlin

Justin S Morrill, Jr

James P Quan

Justin S Morrill

A method for synchronizing a measurement in a communication system. Recent developments in communication systems have resulted in combining the traffic historically carried separately by telephone and data networks. The service provided by such systems is referred to as Voice over Packet (VoP) with the more popular version using the Internet Protocol (IP) commonly referred to as Voice over IP (VoIP). VoP technologies have made maintaining voice quality at high levels more complex by compressing the voice signal and transmitting it in discrete packets. With voice traffic there is the need for timely packet delivery, often in networks that were not originally designed for these conditions. Digitizing analog voice signals often affects voice clarity. Objective tests for voice quality are available but are difficult to synchronize between stations. In methods disclosed pseudo-random analogue signals which emulate white noise are created and used as synchronization signals which enable this synchronization more precisely than previous methods. These signals are relatively unaffected by the codecs commonly used for voice and data compression.

Measurement synchronization method for voice over packet communication systems

Disclosed is a communications measurement matrix display for a protocol analyzer which is used to monitor traffic on a packet-switched network. The display allows the protocol analyser user to see, at a glance, a complete and accurate overview of communications between more than thirty-one nodes on a packet-switched network, over a user selectable range of measurement-time intervals. The matrix display has two modes. One mode shows the source versus the destination nodes of the network as a 32-.times.-32 two-dimensional X-Y grid matrix having thirty one source nodes ordinally indicated along one grid axis and thirty one destination nodes ordinally indicated along the other grid axis. The thirty second ordinal position on each axis designates any nodes other than the first thirty one nodes. A display marker postioned on the grid indicates communication between the source node and the destination node which correspond to the (X,Y), that is, the (SOURCE, DESTINATION), coordinates of the marker. In a second mode, the display shows the node connections only: the display is simply a 32-.times.-32 two-dimensional X-Y grid having thirty two nodes ordinally indicated on each axis without direction, such as source or destination, indicated. The display of the second mode is essentially the display of the first mode folded onto itself. The matrix display, in both modes, is particularly well suited to the IEEE 802.3 Local Area Network packet-switched network. The matrix display is accomplished usng a combination of dedicated hardware and real-time software.

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Colorado Springs, CO, United States of America

Jeffrey Tomberlin