Glossary

TrafficDirector applications performed by a network administrator that concentrate on performing the necessary configuration tasks to functionally link data-monitoring devices to utilities that display the monitored data.

Firmware embedded or software installed on a device.

A collection of one or more agents created by a network administrator. The TrafficDirector application handles an agent group as a single agent, allowing you to collectively monitor network statistics from more than one segment or point on a segment.

Notification that a threshold (rising or falling) established by the user has been met.

Alarm information displayed on the lower half of the Domain Discovery window that includes alarms configured on an agent. You can obtain additional details by selecting a specific alarm.

Periodically takes statistical samples from variables in the SwitchProbe device and compares them with previously configured thresholds. If the monitored variable crosses a threshold, an event is generated. A mechanism is implemented to limit the generation of alarms. This group includes the alarmTable and requires the implementation of the Event group. Elements include alarm type, interval, starting threshold, and stop threshold.

A message sent to all IP addresses defined in the trap community string.

A TrafficDirector application that displays alerts when a threshold is met.

A TrafficDirector application that displays, for a selected domain, all conversations taking place between a pair of hosts.

A TrafficDirector application that displays, for a selected domain, all talkers seen by the agent connected to the network segment.

A port on a switch designated by the switch management console to host a SwitchProbe device or analyzer. This port is most often put in receive-only mode and packets are mirrored to it when the mirroring function is activated.

A TrafficDirector application that displays statistics such as utilization percentage, number of bytes, or number of packets for a selected agent or Frame Relay agent, within a selected domain. These statistics are displayed on a real-time basis as a sliding window according to an established refresh interval.

The method of managing enterprise networks by tracking application flows and their impact on the network.

A TrafficDirector application that displays statistics such as utilization percentage, number of bytes, or number of packets for a selected agent or Frame Relay agent, within a selected domain. These statistics are displayed on a real-time basis as a sliding window according to a selectable refresh interval.

The RMON2 group that counts the amount of traffic, by application protocol, discovered by the SwitchProbe device.

The RMON2 group that counts the amount of traffic, by application protocol, between each pair of network addresses discovered by the SwitchProbe device.

TopN Conversations over a user-defined period, based on packets or octet counts.

A TrafficDirector application that allows you to see statistics of application-level domains on a network segment.

The amount of time from the moment that an application receives a query to when the application produces a response. By subtracting this figure from the total round-trip transmission time, you can determine how much of the delay was caused by the network and how much was caused by server processing time.

The Application Response Time (ART) MIB is a data source built on the RMON2 standard that measures application response time in a network segment. It extends RMON2 to measure the delay seen by application request-response dialogues in a network segment.

A TrafficDirector application, run on agents and application domains supporting this group. It displays the statistics collected by an agent supporting the ART MIB which collects application response time information (retries, traffic load, and response time buckets) for certain applications.

The TrafficDirector application supports the ART MIB framework by extending the domain architecture to include a fourth statistics group called ResponseTime (R), in addition to the three existing groups: Stats (S), Hosts (H), and Conversations (C). The R group is supported for certain application domains. You can enable or disable it (both in the agent and for logging) using Configuration Manager just like any of the other three groups.

See Application Response Time.

A network technology based on transferring data in cells of a fixed size.

An ATM RMON MIB group. ATM per-host statistics count the amount of traffic sent on behalf of each ATM address discovered by the SwitchProbe device. The counters measure InCells, OutCells, number of In Call Attempts, number of In Calls, number of Out Call attempts, number of Out Calls, In Connection Time, and Out Connection Time per host.

An ATM RMON MIB group. ATM per-circuit statistics counts the amount of traffic sent on behalf of each source and destination ATM address discovered by the SwitchProbe device. These groups maintain counters similar to host group on a per-conversation basis rather than on a per-host basis.

An ATM RMON MIB group. Finds and reports the top traffic contributors (conversations) according to associated portSelectGroup criteria.

A TrafficDirector application started on an ATM SwitchProbe device or an ATM switch supporting the ATM RMON MIB. Shows the statistics for both service classes (Abr&Ubr and Cbr&Vbr) for each of the configured port groups. You can change the view to show Call Rates or Cell Rates.

The MIB that is implemented in ATM SwitchProbe devices. As defined in the ATM RMON MIB, a user can collect ATM stats, ATM hosts, and ATM conversations for specific port groups. A SwitchProbe agent implementing this MIB is assumed to boot with predefined port groups. The device, which is either connected between the switch and another ATM device, or is spanning traffic from other ATM port(s), will typically have one port group. All ATM SwitchProbe devices implement RMON1, RMON2, and MIB extensions. You access the ATM RMON functionality in a SwitchProbe device by defining an ATM agent using the Configuration Manager application. The interface number for the SwitchProbe device selects the particular ATM interface. This is required to access the RMON1 and RMON2 statistics on this interface.

The Basic Statistics group in the ATM RMON MIB. Counts the amount of traffic per interface. The counters measure the number of cells, number of call attempts, number of successfully established calls, and connection time.

The action of automatically retrieving data from an agent and storing it in a database. You can retrieve and analyze the data using the different TrafficDirector report.

A Trend Report option that allows you to create a report of critical information on a regular basis (daily, weekly, or monthly).

The Auto Reporter function allows you to schedule reports to be automatically generated on a daily, weekly, or monthly basis.

The daily reports are based on a 24-hour period from 12:00AM one day to 12:00AM the next day, and are generated at 3:00AM on the following day.

The weekly reports are based on a seven-day period from 12:00AM Sunday to 12:00AM the following Sunday and are generated at 3:00AM on Sundays.

The monthly reports are based on the calendar month, 12:00AM on the first of the month to 12:00AM on the first of the next month, and are generated at 3:00AM on the first of the month. The Auto Reporter time ranges or start times are not user configurable.

Compares two similar time ranges in one report. A baseline time range is maintained (protected against purge action) so that baseline data is available at report time. The baseline time range can be one to 30 days. You can baseline both detail and summary data, and you can store up to two baseline time ranges; however, the comparison reports run on any two time ranges where data is available. The baseline comparison is a one-to-one comparison; therefore, no computation of average, min, max, or standard deviation is performed on the baseline data.

Storage of packets, based on filters, for later retrieval.

An ATM unit of segmented data that consists of 53 bytes or octets. Of these, five constitute the header and the remaining 48 carry the data payload. Cell-switching gives maximum utilization of the physical resources.

The protocol-independent, device-discovery protocol that runs on all Cisco-manufactured equipment including routers, access servers, bridges, and switches. Using CDP, a device can advertise its existence to other devices and receive information about other devices on the same LAN or on the remote side of a WAN. Runs on all media that support SNAP, including LANs, Frame Relay, and ATM.

The TrafficDirector command-line interface on UNIX. Accessible at the shell prompt on UNIX; accessible at the DOS prompt on Microsoft Windows. When invoked, displays CLI usage options.

The committed rate, in bits per second, at which the incoming interface trunk and outgoing interface trunk of a Frame Relay network transfers information under normal conditions to the destination Frame Relay end system.

A TrafficDirector application allows you to add and configure agents, agent groups, switches, and Frame Relay agents. Configuration Manager also provides a means for installing domains, logging, traps, and resources on a variety of agents including DLCIs and switch ports.

A TrafficDirector application that allows you to define the number of days that different kinds of data are stored in an SQL report database before being deleted.

A TrafficDirector administrator application that allows you to define access to SQL databases by configuring each database as a SQL server. The TrafficDirector Trend Reporter application generates reports based on information contained within the SQL database.

The three matrix groups are: RMON1, RMON2 nlhost, and alhost. Host groups track the amount of traffic individual hosts are responsible for any layer of the three levels of RMON network model: Datalink and Physical, Network, and Applications.

A alarm-settable, non-negative integer network variable that may be incremented but not decremented. The counter includes statistical variables such as packets, CRC/Align Errors, Jabbers, and Undersize. All alarm-settable variables are counters, excluding those specifically mentioned as gauges and timeticks.

A TrafficDirector application that you can select from any of the three modes---traffic, protocol, or applications. Examples of cross-mode applications include Data Capture, Domain Discovery, and Test Agent.

A custom properties file is created for a specific device (agent, Frame Relay agent, or switch) when you add the device to the TrafficDirector application using the Configuration Manager application. You can modify custom properties files to contain properties such as logging and traps for individual DLCIs and switch ports, and resources such as round trip delays and IP pings.

A custom properties file is specific to the agent for which it was created and cannot be shared among agents.

Processes that run in the background and are disconnected from a process group and terminal. The TrafficDirector application uses specific daemons to create and update tables in the SQL database. Daemons work with related configuration files that rule how and when the daemons are called to perform their roles.

The TrafficDirector application that allows you to capture specific data and store it in a file they have defined. The data can be examined immediately, or at a later date using the Protocol Decode application. (See also: protocol decode.)

The devices and connections of a communications network that connect the communication circuit with an end device (data terminal equipment). A modem is an example of a DCE.

The number the TrafficDirector agent assigns to a DLCI that the SwitchProbe device discovers on the network. Each DLCI is associated with a permanent virtual circuit (PVC).

A DLCI is a channel number attached to data frames to tell the network how to route the data. Frame Relay is statistically multiplexed, which means that only one frame can be transmitted at a time, but many logical connections can coexist on a single physical line. The DLCI allows the data to be logically tied to one of the connections so that when it reaches the network, it knows where to send the data.

A device used in digital transmission that adapts the physical interface on a DTE device to a transmission facility such as T1 or E1. The DSU is also responsible for such functions as signal timing. Often referred to together with CSU, as CSU/DSU.

The part of a data station that serves as a data source, data destination, or both, and provides the data communications control function according to protocols. Data terminal equipment includes such devices as computers, protocol translators, and multiplexers.

A convention that describes the kinds of traffic to be collected at the agent/device. A domain allows you to choose display statistics from a specific traffic stream using TrafficDirector applications.

An alarm generated when certain established conditions are met for a specific domain. An example may be bandwidth utilization by the IP domain. Depending on the type of agent, you can configure domain alarms in the shared or custom properties files.

The TrafficDirector application that allows you to monitor traffic on a network to establish a baseline of normal or expected performance. Domain Discovery displays all domains the agent is configured to monitor, and the level of traffic each domain is responsible for. You can use Domain discovery to confirm that the agent has the domains installed specified in the properties file.

The TrafficDirector administrator application that allows you to define the protocol or generic domain to be used by an agent.

Refers to a group of multiple protocols for which you can collect statistics.

A graphical presentation, over a period of time, of statistics for a selected domain. You can display statistics such as utilization, packets, packet distribution, bytes, vital signs, size distribution, or errors.

Any network or logging daemon event logged to the TrafficDirector application and displayed in Alert Monitor.

Controls the generation and notification of events from this device. Elements include event type, description, last-time event sent.

Run-time configuration of the logging directory, minimum level to log, and expiration time.

Logging of date, time, application name, process ID, thread ID (if applicable), and user name (on UNIX platforms).

Logging to two separate files---one for GUI applications, and one for daemons---with separate configuration parameters for each program type.

A facility to periodically expire log files when they have reached their expire time limit. This facility would run every 24 hours from dbchkd, and would exit when log expiration is complete.

A predefined value (point) placed on a network variable. A falling threshold is crossed when the value of the network variable is equal to or less than the value of the falling threshold.

A process or device that screens network traffic for certain characteristics, such as source address, destination address, or protocol, and determines whether to forward or discard that traffic based on the established criteria.

The TrafficDirector administrator application that allows you to add new filters to the filter list, or edit or delete existing filters.

A format that uniquely describes the specific characteristics of the frame that must be matched for acceptance or rejection of data packets from the data capture buffers. Filter formats are based on the detailed structure of the seven-layer protocol stack that makes up a transmission frame.

Allows packets to be matched by a filter equation. These packets form a data stream that may be captured or may generate events. Elements include bit filter type (mask or not mask), filter expression (bit level), conditional expression (and, or, not) to other filters.

A common and standardized interface designed for data traffic that provides an interface between different vendors' equipment at the User-to-Network Interface (UNI).

A WAN interface set up to monitor a Frame Relay segment.

A data file stored in the $NSHOME/usr directory. This is a custom property file for a Frame Relay agent that contains logging and resources information, and logging information for domains and their groups on DLCIs and VLANs.

A configuration file specific to a particular installation, this file contains a listing of DLCI numbers and the CIR definition for a specific Frame Relay agent. This file name is derived from the first 15 characters of the Frame Relay agent name. The number of lines in this file equals the number of discovered DLCI ports. The TrafficDirector application automatically creates this file, if it is not already present when you use either the TrafficDirector application (before you start Traffic Monitor for a Frame Relay agent), or the dvlearn command-line utility. You can also create this file with an ASCII text editor, or build it incrementally using the Add Frame Relay application within Configuration Manager.

This alarm-settable network variable is a non-negative integer that may increase or decrease. Gauges you can select include Utilization, Beacon Time (TR MAC Stats), Average Response Time (RT Delay).

Provides the means to classify network traffic by protocols that reside in the data link layer of the OSI model (layer 2). You can install generic domains only on SwitchProbe devices. Generic domains let you monitor a logical data stream formed by packets that match filters specified in the domain definition.

The newest version of Ethernet which supports data transfer rates of 1 Gigabit (1,000 megabits) per second. The first Gigabit Ethernet standard (802.3z) was ratified by the IEEE 802.3 Committee in 1998.

With the implementation of HCRMON, 64-bit counters need to be represented by various applications. Due to screen limitations in the GUI applications, it is not possible (or desirable) to display every digit in a 64-bit counter. Therefore, the following convention is followed:

64-bit counters can be displayed in 10-digit or 4-digit format depending on the space available to the application. The magnitude of the number is indicated by a character immediately following the digit string.

High-level serial interface that supports up to 52 Mbps and offers LAN-like performance over a wide area.

Records periodic statistical samples from a network and stores them for later retrieval. Elements include sample period, number of samples, and item(s) sampled.

Contains statistics associated with each host discovered on the network. Elements include host address, packets and bytes received and transmitted, and broadcast, multicast, and error packets.

Prepares tables that describe the hosts that top a list ordered by one of their statistics. The available statistics are samples of one of their base statistics over an interval specified by the management station. Thus, these statistics are rate-based. Elements include statistics, which host(s), sample start and stop period, rate base, and duration.

Cisco Systems term for a Virtual LAN (VLAN).

To continuously send random or garbage data. Normally indicates failed logic or circuits. Member of the RMON1 statistics group.

To make the TrafficDirector application recognize Ethernet and Fast Ethernet ports of the switch, it must "learn" ports of a selected switch. To do so, click the Learn button to the right of the switch list box.

A network segment identified by the SwitchProbe IP address and interface number. This term is equivalent to agent in the TrafficDirector application. Cisco highly recommends that you define locations using meaningful names such as bos-wan-1 or peoria-fddi-2.

How the TrafficDirector application retrieves data from the SwitchProbe device into the server. (See also: auto-logging, report logging, system event logging.)

SQL database to which the TrafficDirector application writes data. The data in this database is used by the Trend Reporter application for generating reports.

The TrafficDirector application that shows statistical history over a preset time period. You define the number of samples and the sample interval are using the Property Editor application. The long-term default number of samples is 50; the sample interval is 1800 seconds (30 minutes).

Standardized data-link layer address required for every port or device that connects to a LAN. Other devices in the network use these addresses to locate specific ports in the network and to create and update routing tables and data structures. MAC addresses are six bytes long and are controlled by the IEEE.

Stores statistics for conversations between sets of two addresses. As the device detects a new conversation, it creates a new entry in its tables. Elements include source and destination address pairs and packets, bytes, and errors for each pair.

A set of parameters that an SNMP management station can query or set in the SNMP agent of a networked device, such as a router.

A term that refers to four of the ten groups of RMON1. These four groups are statistics, history, events, and alarms.

Multiple packets copied by the network that are sent to a specific subset of network addresses. These addresses are specified in the destination address field. Member of the RMON1 statistics group.

Allows multiple logical signals to be transmitted simultaneously across a single physical channel.

The ability to view aggregate information from multiple domains (previous versions of the TrafficDirector application-supported domain-centric views). For example, it may be more useful to save (in the database) TopN hosts per interval across all the domains, rather than a separate list for each domain.

Historical view of individual statistics for one or more segments of the same topology.

An internal probe device that extends (for Ethernet VLANs) the Remote Monitoring (RMON) support provided by the Cisco Catalyst 5000 series of switches. The Network Analysis Module provides RMON and RMON2 support for application monitoring, traffic analysis, and troubleshooting. It acts as a network data-gathering agent and provides network traffic monitoring when used with a client equipped with network-monitoring software.

Counts the amount of traffic sent to and from each network address discovered by the SwitchProbe device.

Counts the number of packets between each pair of network addresses discovered by the SwitchProbe device.

TopN conversations over a user-defined period based on either packet or octet counts.

An adapter used to interface desktop devices (such as personal computers, workstations, and printers) to a LAN.

Nonvolatile random access memory. Program memory designed to hold information during loss of power.

A MIB series of non-negative integers, separated by periods (dots), that delineates the path to the object through the SNMP global naming tree.

A group of fixed-length binary digits, including the data and call control signals, that are transmitted through an X.25 packet-switching network as a composite whole. The data, call control signals, and possible error control information are arranged in a predetermined format. Packets do not always travel the same pathway, but are arranged in proper sequence at the destination side before forwarding the complete message to the addressee.

Allows packets to be captured after they flow through a channel. Information gathered from a packet capture includes size of buffer for captured packets, full status (alarm), and the number of packets captured.

A virtual circuit that is permanently established. PVCs save bandwidth associated with circuit establishment and tear-down in situations where certain virtual circuits must exist all the time.

ICMP echo message and its reply. Often used in IP networks to test the reachability of a network device.

An inquiry from the TrafficDirector application asking for a specific set of data (for example, statistics) from a SwitchProbe device.

An interface on an internetworking device, such as a router. In IP terminology, a port is an upper-layer process that receives information from lower layers. Ports are numbered, and each numbered port is associated with a specific process.

An ATM RMON MIB group that defines the ports to be included in a particular stats, host, or matrix collection. This group can collect different ports into one group, so that aggregate collection of stats on the selected ports can be done.

Includes information about the RMON groups supported by the SwitchProbe device, the hardware and software revisions of the device, how to update the firmware, serial-line configuration for out-of-band management, including modem setup commands, and configuration of each interface.

Consists of domains and their associated (modifiable) parameters that determine how statistics on data (matching the domain's criteria) are to be collected and logged. Properties files also provide for the establishment (or removal) of traps/alarms per domain. You install properties files on a device using the Configuration Manager application. (See also: shared properties file and custom properties file.)

The application within Configuration Manager that allows you to define shared and custom properties for an agent, agent group, switch, or Frame Relay.

A TrafficDirector application that allows you to examine captured data packets stored in a file that you defined. (See also: data capture.)

Presents an inventory of those protocol types the SwitchProbe device is capable of monitoring.

Counts the number of packets and octets for the different protocols detected on the network segment.

One of two types of domains (the other is generic). Protocol domains allow you to classify traffic by network- and application-layer protocols.

The TrafficDirector application that allows you to view various statistics for a selected agent or Frame Relay agent within a selected domain.

The TrafficDirector application that allows you to view in graphic format the utilization, packet rate, or kilobyte rate for a predefined domain group.

The TrafficDirector application that allows you to examine more closely the activity for a specific domain. (See also: Protocol Monitor.)

A feature of the TrafficDirector Property File that allows you to configure an agent to send out SNMP get requests to a particular host to retrieve the value of a specific MIB object.

Allows you to read the MIB on a switch MIBs. (See also: write community.)

A software-based probe for monitoring RMON2 statistics (Microsoft Windows-based).

The TrafficDirector feature that allows you to remotely log into a SwitchProbe device and perform various administrative functions.

A network management protocol that allows you to gather network information at a single workstation. Unlike SNMP, which gathers network data from a single type of management information base (MIB), RMON1 defines nine additional MIBs that provide a more comprehensive set of data about network usage. (Refer to RFC 1757 for more information on RMON.) For RMON to work, network devices, such as hubs and routers, must be set up to support it.

A standard that defines network monitoring above the data-link layer, allowing you to analyze traffic by protocol.

This group allows you to find out which groups and instances of a group that a SwitchProbe device supports.

The TrafficDirector application that allows you to define report format, graph type, and sorting statistics for host- and conversation-related reports.

The kind of information that will be included in a report and how it is displayed and organized. Report template files have the extension of .rt and reside in the $NSHOME\usr directory. You can create and edit report templates using Report Editor.

Alarms that monitor results of an agent performing round trip delays (pings) or proxy SNMP (SNMP gets) of whole integer MIB object values.You can only configure resource alarms in an agent's custom traps file (agent_name.act).

The TrafficDirector application that allows you to monitor the resources of any SNMP device by downloading MIB variables selected from a list to the agent.

Allows you to enter the number of times you want the TrafficDirector application to attempt to reach the switch if there is no response. The value must be an integer between 1 and 1000.

The TrafficDirector application that allows your to view statistics and errors specific to Token Ring and FDDI networks.

The threshold that is crossed when the value of the network variable is equal to or greater than the rising threshold.

A TrafficDirector protocol-level application that allows you to configure an agent to ping a specified IP address to check network connectivity to a remote device.

Refers to how the TrafficDirector application can direct full RMON2/RMON analysis to any switch port you select. Roving involves connecting a SwitchProbe device to an analyzer port on the switch, then mirroring traffic from a selected switch port to the specified analyzer port. The SwitchProbe device then examines the traffic as if it was receiving the traffic directly.

The ability to use software to control and direct full RMON to any switch port on demand. (See also: mini-RMON.)

The TrafficDirector traffic-level segment monitoring application that allows you to display a variety of tabular (formatted text) statistics, depending on the device you selected in the TrafficDirector main window---agent, switch port, or Frame Relay DLCI.

The TrafficDirector traffic-level segment monitoring application that allows you to display statistical data available from a particular agent and generic domain in graphical format.

Contain properties---such as domains you want to monitor, logging for domains, and traps---that you can install (using Configuration Manager) on a single device (agent, Frame Relay agent, or switch), or applied consistently across groups of such devices to compare similar statistics for multiple network segments.

Shared properties files are designed to be shared between different devices of the same topology. You can create one shared properties file, install it on multiple agents, and monitor the same information across multiple network segments.

A TrafficDirector application that shows statistical history over a preset time period. You define the number of samples and the sample interval using the Property Editor application. The short-term default number of samples is 50; the sample interval is 30 seconds.

Another name for SNMP2, an enhanced version of the Simple Network Management Protocol (SNMP) with features required to support larger networks operating at high data transmission rates. SNMP2 also supports multiple network management workstations organized in a hierarchical fashion.

A standard for network management that uses a common software agent to manage local and wide area network equipment from different vendors; part of the Transmission Control Protocol/ Internet Protocol (TCP/IP) suite and defined in RFC 1157.

A combination of proposal updates to SNMP, most of which deal with security.

A device or software subsystem that functions as a protocol analyzer and statistics probe on a network.

An SQL database to which another TrafficDirector application is logging.

Contains statistics measured by the SwitchProbe device for each monitored interface on this device. Elements include packets dropped, packets sent, bytes sent (octets), broadcast packets, multicast packets, CRC errors, runts, giants, fragments, jabbers, collisions, and counters for packets ranging from 64-128, 128-256, 256-512, 512-1024, and 1024-1518 bytes in size.

A dbupdate configuration file parameter. This interval shows the number of days that information ages before the aging daemon deletes it from the daily table. Daily aging must be greater than one day. The default value for protocol and segment statistics from the Summary (Daily) table is 366 days; for host, conversation, and IP ping statistics, 31 days.

A device that microsegments a network to dramatically increase the number of network segments, reducing the number of users per segment, thereby increasing the bandwidth available to each user. A switch also segments networks into logically defined workgroups called VLANS (virtual LANs).

Agent firmware embedded on switch ports. Depending on the type of switch used, you can monitor and collect mini-RMON and/or SMON group statistics. For example, the Cisco Catalyst 1600 switch supports mini-RMON; the Cisco Catalyst 5000-series switches supports SMON.

The port to which the roving or proxy agent is connected.

A hardware device that monitors and collects RMON statistics. Individual SwitchProbe devices are often placed on network segments to monitor network usage and trends. When you configure a SwitchProbe device with the TrafficDirector application, you can view data about the entire network from a central location. SwitchProbe devices and network manager applications communicate using standard SNMP commands sent over TCP/IP.

The agent firmware embedded on a SwitchProbe device to monitor and collect RMON1 and RMON2 group statistics.

A virtual link, with variable endpoints, established through an ATM network. With an SVC, you define the endpoints when the call is initiated; with a PVC, you predefine the endpoints. A single virtual path may support multiple SVCs.

Any entity that is talking on a network segment.

A TrafficDirector application used to quickly determine if a selected agent (either a common agent or a Frame Relay agent) or a selected switch is operational.

A limit value associated with a specific parameter or attribute of device or network performance. Detection of this value triggers an appropriate response from the local or remote systems or device. For example, when a threshold value is crossed, a warning message can be sent or a module or port can be partitioned. (See also: rising threshold and falling threshold.)

The field that allows you to enter the length of time (in seconds) that you want the TrafficDirector application to wait before retrying an SNMP request. The value must be an integer between 1 and 1000.

Token-passing LAN developed and supported by IBM. Token Ring runs at 4 or 16 Mbps over a ring topology.

Token Ring-specific information.

A three-dimensional generic graph that includes every entity that is talking on a network segment.

The port on a switch that is designated by the switch management console to host a SwitchProbe device or analyzer. Most often this port is put in receive-only mode and packets are mirrored to it when you activate the mirroring function.

Techniques for controlling traffic load and balance across a network that allow links to operate at high levels of utilization by scaling back lower-priority, delay-tolerant traffic at the edge of the network when congestion begins to occur.

The TrafficDirector application that provides you with a top-level view of the network by monitoring selected MAC-layer statistics for the agent (agents must contain the RMON domain) or switches selected.

A term used interchangeably to describe both the thresholds configured in an agent to monitor specific conditions on a segment, and what occurs when the specified conditions occur.

Used to create reports from data which is collected over time and stored in an SQL database. There are two distinct components of the Trend Reporter: logging, which involves configuring SwitchProbe devices, configuring logging daemons which poll SwitchProbe devices for data, and storing the data in an SQL Database, and reporting, which involves retrieving SQL data and presenting report information. To configure SwitchProbe devices and logging parameters, use Configuration Manager. To run reports, use Trend Reporter.

Custom history tables based on supported OIDs.

A menu option that allows you to choose statistics that you want to look at.

A logical circuit set up to ensure reliable communications between two network devices.

A closed, logically defined community of interest, such as a department or project team. VLANs allow you to build software LANs regardless of each user's physical location. VLANs constitute a broadcast domain---similar to a subnet---within which broadcasts are contained. Routers are required for inter-VLAN communication.

A TrafficDirector term for base-level statistics for each port. A default display of Traffic Monitor.

Enables you to enter the switch write community name. If the name you enter matches the established write community name for the switch, the TrafficDirector application can write to the MIBs on the switch. Otherwise, the TrafficDirector application will not be able to write to the MIBs on the switch. (See also: read community.)

Allows you to take a closer look at a specific interval of a TrafficDirector history report or a section of data samples at a lower display resolution by using the mouse to select a start and end time for the zoom.