Hewlett-packard Company

Fluke Corporation

William R Marbaker

Paul S Swanson

Gordon A Jensen

Thomas S Wisdom, Jr

Scott A Godlew

Jeffrey H Smith

Mark D Keisling

Jeffrey Alan Hughes

Christopher A Clabaugh

A circuit for sensing network speed in a test instrument for local area networks (LANs) is provided. After coupling the test instrument to the LAN of unknown speed, a link pulse is found among the twisted-wire pairs so that the test instrument is configured for the transmit and receive pairs. The link pulse is then coupled to a comparator that compares the received voltage against a predetermined reference voltage level to develop a trigger signal. The trigger signal is received by a timer circuit which measures time values from the link pulse. The time values are collected by a microprocessor are then compared against a decision value to reach a decision whether the test instrument is coupled to a link running 10BASE-T protocol, 100BASE-T protocol, or a 10/100 dual-speed device. After the decision has been determined, the appropriate chipset is then powered up and coupled to the LAN, thereby minimizing battery drain and preventing errors from being introduced in the LAN by the test instrument.

Circuit for determining local area network speed

A network analysis instrument employs a CPU, display and field programmable gate array circuitry to receive network data and detect various error conditions. Percent utilization is determined and information pertaining thereto is displayed to provide a user with information regarding network operating conditions. Ghosts are detected as well as collisions, jabber conditions and runt conditions.

Method and apparatus for network analysis

A system and method for displaying information on computer screens. The present invention operates in a computer system having a windowing system. The present invention performs its functions without placing a great burden on computer system resources. The present invention contains functions for displaying information in line graphs, bar charts, tables, gauge displays, and pie charts. The present invention may be used to implement statistical dashboard displays for protocol analyzers which monitor token ring and ethernet networks.

Method for displaying pie chart information on a computer screen

System and method for distinguishing duplicate source address replies caused by interconnecting devices connected to a local area network and duplicate source address replies caused by non-interconnecting devices connected to the local area network. The present invention may be implemented through an analyzer. The method includes the following steps: In step 1, the present invention sends a first Address Resolution Request packet for a first Internet Protocol target address. In step 2, all Internet Protocol source address responses replying to the first Address Resolution Request packet are catalogued in a first reply set. In step 3, a second Address Resolution Request packet for a second Internet protocol target address is sent on to the network. In step 4, all Internet Protocol source address responses replying to said second Address Resolution Request packet are catalogued in a second reply set. In step 5, the first reply set is intersected with the second reply set resulting in an intersection set. In step 6, subtracting the first reply set from the intersection set to determine if there are any unique responders.

Growing community of inventors

Colorado Springs, CO, United States of America

William R Marbaker