Abstract: A method of processing data received at a local system in response to polling a remote device, wherein the local system includes a local clock, the method involving: sending a first poll to the remote device; receiving a response from the remote device to the first poll, the response to the first poll containing data and a time stamp indicating when the remote device responded to the first poll; for the data received in response to the first poll, computing a first time by using both a time that was derived from the local clock for a previous poll of the remote device and also the time stamp contained in the response to the first poll; comparing the computed first time to information that the local system stored in connection with the first poll, wherein the information that the local system stored in connection with the first poll was derived from the local clock; and determining how to process the data received in response to the first poll based on comparing the computed first time to the information that

Abstract: A method provides for merging lists of newly found and old network elements. The method comprises receiving the list of newly found elements and deriving a potential key value for a portion of the newly found elements from configuration data associated therewith and a key format. The method also updates one of the old elements with the configuration data of a newly found keyed element having the same key. The method compares attributes of newly found elements for components to attributes of old network elements for attribute matches and reports matches. The report lists matching old elements and newly found elements as unresolved if either one does not have a unique key.

Abstract: Systems and methods for automated monitoring and management of distributed applications, client/server databases, networks and systems across heterogeneous environments. Distributed, automated intelligent monitoring agents use embedded sensing technology which is knowledgeable of application protocols, to monitor continuously the network environment in real time. To this end, the monitoring agent can be located on each client and server in the network. The monitoring agent can couple to the communications stack for monitoring the data that is being passed between the client and the network, of a server in the network. The data can be collected and employed for trouble shooting trend analysis, resource planning, security auditing, and accounting as well as other applications. Also included is a controller for remotely coordinating the data gathering process from the various clients and servers.

Abstract: A method provides for merging lists of newly found and old network elements. The method comprises receiving the list of newly found elements and deriving a potential key value for a portion of the newly found elements from configuration data associated therewith and a key format. The method also updates one of the old elements with the configuration data of a newly found keyed element having the same key. The method compares attributes of newly found elements for components to attributes of old network elements for attribute matches and reports matches. The report lists matching old elements and newly found elements as unresolved if either one does not have a unique key.

Abstract: A method of displaying information relating to performance of a computer resource over a preselected period of time, wherein the computer resource is connected to a communication network and the method includes the steps of: from a location on the network that is remote from the computer resource, periodically sampling data relating to performance of the resource so as to generate stored values for a preselected performance variable for that resource, wherein the periodic sampling takes place over a preselected period of time and the preselected performance variable takes on values within a specified range of possible values; dividing the specified range of possible values for the preselected performance variable into a plurality of subranges; for each subrange, determining for what proportion of the preselected period, the values of the preselected performance variable fall within that subrange; and for each subrange, displaying in graphical form the proportion of the preselected period of time that the valu

Abstract: A method for collecting and reporting monitored data for network traffic, which has been accumulated by a plurality of remote probes. The method includes making a series of polling requests for lists of monitoring data to each probe and receiving the requested lists. Each list has traffic count values that are identified by at least a sampling time, a source address, a destination address and a probe identifier. The method also includes calculating the traffic observed by each probe between successive sampling times and apportioning the calculated traffic data among a single set of consecutive temporal intervals and selecting best counts to avoid overcounting.

Abstract: Monitoring is done of communications which occur in a network of nodes, each communication being effected by a transmission of one or more packets among two or more communicating nodes, each communication complying with a predefined communication protocol selected from among protocols available in the network. The contents of packets are detected passively and in real time, communication information associated with multiple protocols is derived from the packet contents.

Abstract: A method of displaying information relating to performance of a computer resource over a preselected period of time, wherein the computer resource is connected to a communication network and the method includes the steps of: from a location on the network that is remote from the computer resource, periodically sampling data relating to performance of the resource so as to generate stored values for a preselected performance variable for that resource, wherein the periodic sampling takes place over a preselected period of time and the preselected performance variable takes on values within a specified range of possible values; dividing the specified range of possible values for the preselected performance variable into a plurality of subranges; for each subrange, determining for what proportion of the preselected period, the values of the preselected performance variable fall within that subrange; and for each subrange, displaying in graphical form the proportion of the preselected period of time that the valu

Abstract: A local area network (LAN) topology monitor including segment monitor nodes which report the presence of new end nodes to a network manager node. The segment monitors send a test-node message when requested by the network manager and inform the network manager of any test-node messages originating from other segments. The network manager uses the sequence of received new-node messages and test-node messages to determine the topology of the LAN. If one segment monitor reports a new node, the new node must be connected to the same segment as the reporting monitor. If multiple segment monitors report the presence of a new node, the network manager requests each reporting segment monitor to send a test-node message. Since the segment monitors report test-node messages received from other segment monitors, if only one segment monitor responds as having received a test-node message, then that segment contains the new node. Otherwise, the new node is off-segment.

Abstract: An access controller for peer-to-peer communication networks which monitors the data packets transmitted between stations, determines when an access that needs to be controlled is being made, and then either destroys the packet or transmits one or more packets which appear as legitimate message packets to the stations but which, in fact, terminates or alters the communication path between the two stations. Since the invention is free of any particular protocol restrictions, it can be implemented with any type of protocol and at any layer of that protocol. And since the access control mechanism is neither part of the physical communication path nor part of the communication primitives, the stations cannot detect, in any direct sense, that their access is being controlled, and they do not need to be programmed to follow any special control protocols, or to use encryption.

Abstract: A local area network modem which meets the stringent signalling requirements of the IEEE 802.4 standard. The modem supports loopback commands by insuring that the receiver and transmitter portions are in phase-synchronism, regardless of the physical distance between the modem and upper layer control circuitry. The transmitter also uses only two digital signal wires to specify which of a number of functions are to be performed by the transmitter analog components. An automatic gain control (AGC) circuit is included which eliminates a number of problems associated with prior designs. In particular, the modem's receiver monitors itself to automatically correct drift in phase and gain control adjustment, without intervention from the upper layer.

Abstract: A symbol detection and correction scheme for local area network modems, especially those which receive one of three symbols at any given time, such as those operating in accordance with the IEEE 802.4 standard. The invention significantly improves the bit error rate observed by the layer above the modem. The modem operates on a received signal with a pair of slicers. One slicer operating as a two-symbol detector, and a second slicer operates as a three-symbol detector. A receiver state machine is used to keep track of which portion of a frame is currently expected to be being received. Depending upon the particular context, one or both of the slicer outputs are used by the state machine to determine which of the three symbols was received. For example, when the receiver is in a state where only one of two data symbols are expected, and no control symbols are expected, only the two-symbol slicer output is used.

Abstract: The invention is a network monitor that passively detects sequences of control frame transmissions. Detected control frame sequences are compared to a model of the expected exchange of control frames. The monitor concludes that a malfunction has occurred when the detected control frame sequences do not match the frame sequences indicated by model. The monitor is quite useful with a network that uses a token passing protocol, since it can determine whether a particular station is working improperly by tracking whether the token is passed in the order proscribed by the expected token-passing sequence in the model. The monitor can detect and diagnose many types of network malfunctions. The monitor also observes and maintains statistics on network data traffic and configuration information, in real time. Since the monitor independently tracks which station has the token, statistics are developed on how much traffic is passing to and from bridges.