Glossary

A

Agent

An Agent is a software process that responds to SNMP queries to provide information about a network-connected device.

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Ancillary

Auxiliary, supplementary.

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B

Blocking calls

Blocking calls are calls that monopolize the Davicom telephone line for long periods of time and prevent the unit from signalling alarms. Examples are: voice, terminal, fax, pager (voice digital, alphanumerical), and DavNet Dial-up calls. Note however that if the Davicom also has an IP connection, blocking calls will not be an issue.

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D

DHCP

The Dynamic Host Configuration Protocol is a network management protocol used on UDP/IP networks whereby a DHCP server dynamically assigns an IP address and other network configuration parameters to each device on a network so they can communicate with other IP networks.

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DNS

The Domain Name System is a hierarchical and decentralized naming system for computers, services, or other resources connected to the Internet or a private network that associates various information with domain names assigned to each of the participating entities.

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DTMF

Dual-tone multi-frequency signaling is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers.

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E

ESD

Electrostatic discharge is the sudden flow of electricity between two electrically charged objects caused by contact, an electrical short, or dielectric breakdown.

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F

Factory Reset

Restoring a device’s system back to its original “ready for delivery from factory” state and erasing all of its internally-stored data.

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Firmware

A low-level computer software that controls the hardware of a device.

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FTP

The File Transfer Protocol is a standard network protocol used for the transfer of computer files between a client and server on a computer network.

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H

HTTP

The Hypertext Transfer Protocol is an application protocol for distributed, collaborative, hypermedia information systems.

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HTTPS

Hypertext Transfer Protocol Secure is an extension of the Hypertext Transfer Protocol (HTTP) that is used for secure communication over a computer network, and is widely used on the Internet.

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I

I/O

Input/output is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system.

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M

Manager

A Manager is an application that manages SNMP agents on a network by sending commands (SETs) to control devices, requesting responses (GETs), and listening for agent-issued alarms (TRAPs).

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MIB

Related to SNMP, MIB stands for Management Information Base. It is a specially formatted text file that contains all the data that is needed to properly use SNMP on a piece of equipment. It provides details like value, type, range of values, description of commands, measurement units, etc. Every SNMP-capable device has at least one MIB related to it.

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MIB Browser

Related to SNMP, a MIB Browser is a computer program that allows one to examine MIB files to find information about OID’s. For example, using a MIB browser could allow the measurement range of a specific value, or its data type to be known.

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Modbus

Modbus is a communication protocol developed by Modicon systems. It is a method used for transmitting information over serial lines between electronic devices. The device requesting the information is called the Modbus Master and the devices supplying information are Modbus Slaves.

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Modem

Hardware device that converts data into a format suitable for a transmission medium so that it can be transmitted from computer to computer (historically over telephone wires). It is used to communicate with Davicom units over dial-up lines.

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N

NTP

The Network Time Protocol is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.

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O

OID

Related to SNMP, OID stands for Object IDentifier. It is a unique identification number that is attached to an Object within an SNMP-capable device, like an Input, an Output an address etc.

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Opto-isolated

In electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal.

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P

PDU

Power Distribution Unit.

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Ping

Computer network administration software utility used to test the reachability of a host on an Internet Protocol (IP) network.

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Power Bar

Multi-outlet power distribution device.

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PSU

Power Supply Unit.

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R

Rectifier

A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction, for easier detection.

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RF

Radio frequency is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz.

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RoHS

The Restriction of Hazardous Substances Directive restricts the use of hazardous materials in the manufacture of various types of electronic and electrical equipment.

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RTP

The Real-time Transport Protocol is a network protocol for delivering audio and video over IP networks.

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RTSP

The Real Time Streaming Protocol is a network control protocol designed for use in entertainment and communications systems to control streaming media servers.

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RTU

A remote terminal unit is a microprocessor-controlled electronic device that interfaces objects in the physical world to a distributed control system or SCADA (supervisory control and data acquisition) system by transmitting telemetry data to a master system, and by using messages from the master supervisory system to control connected objects.

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RU

Rack Unit

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S

SMTP

The Simple Mail Transfer Protocol is a communication protocol for electronic mail transmission.

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SNMP

Simple Network Management Protocol is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. There are SNMP Agents and ASMP Managers. An agent is a software process that responds to SNMP queries to provide information about a network-connected device. A manager is an application that manages SNMP agents on a network by sending commands (SETs) to control devices, requesting responses (GETs), and listening for agent-issued alarms (TRAPs).

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SNMP GET

SNMP command that reads or polls data from a device.

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SNMP SET

SNMP command that writes or sends data to a device.

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T

TCP

The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network.

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TRAP

SNMP single-event message that is sent from one device to another (destination receiver). Generally used to signal an alarm.

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V

Value Type

The type or kind of value to expect from an SNMP GET (read) or to provide for an SNMP SET (write). For example: Integer, DisplayString, IP Address…

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VDC

Volts DC

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