Active Directory (AD)
The centralized directory database that contains user account information and security for the entire group of computers on a network.
Active Directory Domain Services (AD DS)
The active directory service that manages the process that allows a user to sign on to a network from any computer on the network and get access that AD allows.
API (Application Protocol Interface) call
The process an application uses to make a request of the OS.
Application Layer
The 7th layer of the OSI model. Enable software programs to negotiate formatting procedural, security, synchronization, and other requirements with the network.
Application Resolution Protocol (ARP)
The core protocol in the TCP/IP suite that belongs in the network layer of the OSI model. Contains the MAC Physical Address of the host, or node, and then creates a local database that maps the MAC to the host IP Logical Address.
Backbone
The central conduit of a network that connects network segments and significant shared devices (routers, switches, and server) and is sometimes referred to as "A network of networks.
Bandwidth
1) The amount of traffic, or data transmission activity, on a network. 2) A measure of the difference between the highest and lowest frequencies that a medium can transmit.
Best-Effort Protocol
A type of transport layer protocol that services a request without requiring a verified session and without guaranteeing delivery of data.
Bus topogy
A topology in which a single cable connects all nodes on a network without intervening connectivity devices.
Call Tracking System
A software program used to document technical problems and their resolutions; also known as help desk software.
Campus Area Network (CAN)
A network of connected LANs within a limited geographical area such as the buildings on a University Campus.
Catastrophic Failure
A failure that destroys a component beyond use.
Client-Server Applications
Data or a service requested by one computer from another.
Client-Server Network Model
A network where resources are managed by the NOS via a centralized directory database.
Connectionless Protocol
A type of transport layer protocol that services a request without requiring a verified session and without guaranteeing delivery of data. (B-EP)
Connection-Oriented Protocol
A type of transport layer protocol that require the establishment of a connection between communicating nodes before it will transmit data.
Convergence
The use of data networks to carry voice, video, and other communications services in addition to data.
Data Link Layer
The second layer in the OSI Model. Bridges the networking media with the network layer. Its primary functions is to divide the data it receives from the network layer onto frames that can then be transmitted by the physical layer.
Data Link Layer Address
The process by which devices determine which device may access the network at any given time.
Datagram
A UDP message.
Decapsulation
Removing a header or trailer from a lower OSI Layer.
Delay-Sensitive
Transmissions that will suffer significantly compromised user experiences if portions of the transmission are delayed such as with voice and video transmissions.
Demarcation Point (Demarc)
The point of division between a telecommunications service carrier's network and a building's interval network.
Domain
In the context of windows server NOSs, a group of users, servers, and other resources that share account and security policies through a windows server NOS.
Electrostatic Discharge (ESD)
The transfer of electrical charge between two bodies, such as when a technician touches a computer component.
Emergency Alert System
A system that typically generated loud noise sounds and flashing lights in response to a fire. The system might also be able to send alert messages to key personnel or make network wide announcement.
Encapsulation
The process of adding a header to the data inherited from the layer above.
Fail Close
System default that denies access during a system or network failure.
Fail Open
System default that allows access during a system or network failure.
File Server
A specialized server that enables clients to share applications and data across their network.
File Service
The functions of a file server that allow users to share data files, applications, and storage areas.
Fire Suppression System
Any system designed to combat the outbreak of a fire. A FSS might include an emergency alert system. Fire extinguishers, emergency power off switch and ore suppression agent such as foaming chemical.
Fragmentation
A network layer service that subdivides packers into smaller packets when those packets exceed the maximum size for the network.
Frame
The entire data link layer message, including the header, payload, and trailer.
FTP (File Transport Protocol)
An application layer protocol used to send and receive files via TCP/IP. Uses port 20 for data and port 21 for file transfer control information.
Global Account
A user's domain-level account, also called a global username or network ID, which is assigned by the network admin and keep in active directory.
Grounding
Connecting a device directly to the Earth so that, in the event of a short, the electricity flows into the Earth rather than out of control through the device.
Hardware Address
The process by which devices determine which device may access the network at any given time.
Header
An area at the beginning of a payload where protocols add their control information.
Heating, Ventilation, and Air Con (HVAC) System Host
A system that controls the environment in a data center, including the temperature, humidity, airflow, and air filtering.
HTTP (HyperText Transfer Protocol)
An application layer protocol that formulate and interprets requests between web clients and servers. Uses the TCP port 80.
HTTPS (HTTP Secure)
The url prefix that indicates that a webpage require its data to be exchanged between client and server using SSL or TLS encryption. Uses TCP port 443.
Hybrid Topology
A physical topology that combines characteristics of more than one simple physical topology.
ICMP (Internet Control Message Protocol)
A core protocol in the TCP/IP suite that notifies the sender that something has gone wrong in the transmission process and that packets were not delivered.
IMAP4 (Internet Message Access Protocol, v4)
The most commonly used form of the internet message access protocol.
IP (Internet Protocol)
A core protocol in the TCP/IP suite that operates in the network layer of the OSI Model and provides information about how and where data should be delivered IP is the subprotocol that enables TCP/IP -> Internetwork.
IP Address
A unique network layer address assigned to each node on a TCP/IP network. IPv4 address consist of 32 bit divided into 4 octets or bytes. IPv6 address are composed of 8 16-bit fields = 128 bits.
Knowledge Base
A collection of accumulated insights and solutions to the problems encountered on a particular network.
Layer 2 Switch
The least intelligent type of switch because it is nonprogrammable. Incapable of transmitting messages outside of the LAN.
Link Layer
The second layer in the OSI Model. Bridges the networking media with the network layer. Its primary functions is to divide the data it receives from the network layer onto frames that can then be transmitted by the physical layer. (Data Link Layer).
Link Layer Switch
The least intelligent type of switch because it is nonprogrammable. Incapable of transmitting messages outside of the LAN. (Layer 2 Switch)
Local Account
A windows access account that works only on that one computer.
Local Area Network (LAN)
A network of computers and other devices that typically is confined to a relatively small space, such as one building or even one office. Each node can communicate directly with others.
Logically Topology
A characteristic of network transmission that reflects the way in which data is transmitted between nodes. May differ from its physical topology.
Loss-Tolerant
Transmission that can tolerate occasional loss of data without compromising that user experience.
Metropolitan Area Network (MAN)
A network of connected LANs within a limited geographical area, such as multiple city government buildings around a city's center.
Material Safety Data Sheet (MSDS)
Instructions provided with dangerous substance that explain how to properly handle these substances and how to safely dispose of them.
Multicast Distribution
A client-server model with one server and many clients.
Network
A group of computers and other devices (printers) that are connected by and can exchange data via some type of transmission data, such as, cable, wire, or the atmosphere.
Network Adapter
The device that enables a workstation to connect to the network and communicate with other computers. NICs are manufactured by several different companies and come with a variety of specifications.
Network Interface Card (NIC)
The device that enables a workstation to connect to the network and communication with other computers. Manufactured by several different companies and come with a variety of specifications.
Network Layer
The third layer in the OSI Model. Called Internet Layer is responsible for moving messages from one node to another until they reach the destination host.
Network Operating System (NOS)
The software the runs on a server and enables the server to mange data, users, groups, security, application, and other networking functions. The most popular NOS UNIX, Linux, and Microsoft Windows server.
Network Services
The resources a network makes available to its users, including application and the data provided by these applications.
Node
Any computer or other device on a network that can be addressed on the local network.
Onboard Network Port
A port that is integrated into a computer's motherboard.
Occupational Safety and Health Admin (OSHA)
The main federal agency charged with regulating safety and health in the workplace.
Open Systems Interconnection (OSI)
A model for understanding and developing computer to computer communication developed in the 1980s. It divides networking functions around 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
Packet
The entire network layer message, which includes the segment (TCP) or datagram (UDP) from the transport layer, plus the network layer header.
Personal Area Network (PAN)
A network of personal devices, such as a cell phone, laptop, and bluetooth printer.
Patch Panel
A well-or-rack-mounted panel where cables converge in one location.
Payload
Data that is passed between applications or utility programs and the operating system, and includes control information.
Peer-to-Peer (P2P) Network
A network in which every computer can communicate directly with every other computer by default, no computer on a P2P network has more authority than another. However, each computer can be configured to share some resources and inaccessible to other node.
Personal Protective Equipment (PPE)
Wearable equipment such as goggles that might be require in the workplace to increase safety of workers.
Physical Address
The process by which devices determine which device may access the network at any given time. (Same as Data Link Layer)
Physical Layer
The lowest, or first, layer of the OSI Model. Responsible only for sending bits via a wired or wireless transmission.
Physical Topology
The physical layout of the media, nodes, and devices one a network. Does not specify device types, connectivity methods, or addressing schemes, categorize into 3 fundamental shapes: bus, ring, and star. Mix would be hybrid.
Plenum
The area above the ceiling tile or below the subfloor in a building.
Point-to-Multipoint Model
A communications arrangement in which one transmitter issues signals to multiple receivers. The receivers may be undefined, as in a broadcast transmission or defined as in a non-broadcast transmission.
Point-to-Point Model
A data transmission that involves one transmitter and one receiver.
Post Office Protocol, v3 (POP3)
The mostly commonly used form of the post office protocol.
Port Number
The address on a host where an application makes itself available to incoming data.
Presentation Layer
The 6th layer of the OSI Model. Protocols are responsible for reformatting, compressing, and/or encrypting data in a way that the application on the receiving end can read.
Print Services
The network service that allows printers to be shared by several users on a network.
Protocol
A standard method or formatting for communication between network device.
Protocol Data Unit (PDU)
A unit of data at any layer of the OSI Model.
Quality of Service (QoS)
The result of specifications for guaranteeing data delivery with in a certain period of time after their transmission.
Rack
An open or enclosed cabinet that holds network devices such as switches, routers, servers, and or patch panels.
Remote Desktop Protocol (RDP)
An Application layer protocol that uses TCP/IP to transmit graphics and text quickly over a remote client-host connection. Carries session licensing and encryption information.
Remote Application
Installed application and executed on a server and is presented to a user working at a client computer.
Remote Desktop
A feature of windows operating system. That allows a computer to act as remote host and can be controlled from a client also running windows.
Remote Desktop Services
A feature of windows server 2008 and later editions of windows server that allows technicians to manage remote application.
Ring Topology
Network Layout in which each node is connected to the nearest nodes so that the entire network forms a ring. Data transmitted in one direction around the ring. Workstation accepts and respond to packets address and forwards to next.
Router
A layer 3 device that uses logical address information to direct data between two or more networks and can help find the best path for the traffic to get from one to another network.
Real-Time Transport Protocol (RTP)
Application Layer protocol used with voice and video transmission. Operates on top of UDP and proves information about packer sequence to help receiving nodes detect delay and packet loss. Assigns packets a time stamp that corresponds to when the data in
Scalable
The property of a network that allows you to add nodes or increase its size easily.
Secure Shell (SSH)
A connection utility that provides authentication and encryption with SSH you can securely log on a host, execute commands on that host and copy files to or from that host. SSH encrypts data exchange.
Segment
(1) A unit of data that results from subduing a larger protocol data unit. (2) A part of a network usually a segment is composed of a group of nodes that share the same communications for all their traffic.
Session Layer
The 5th layer in the OSI Model. Describes how data between application is synced and recovered if messages don't arrive intact at the receiving application.
Secure File Transfer Protocol (SFTP)
A protocol available with the proprietary version of SSH that copies files between hosts securely like FTP,SFTP. First establishes a connection with a host and allows a remote utility to browse directories, list, and files. SFTP encrypt before sending.
Simple Mail Transfer Protocol (SMTP)
The application layer TCP/IP subprotocol responsible for moving messages from one mail server to another.
Secure Sockets Layer (SSL)
A method of encrypting TCP/IP transmission including web pages and data entered into web forms en route between the client and server using public key encryption technology.
Star Topology
A physical topology in which every node on the network is connected through a central device.
Star-Bus Topology
A hybrid topology in which groups of workstations are connected in a star fashion to connectivity devices that are networked via a single bus.
Static Electricity
An electrical charge at rest. When that charge is transfer between two bodies, it creates an electrostatic discharge or ESD.
Switch
A connectivity device that logically subdivides a network into smaller, individual collision domains. Operates at the Data Link Layer of the OSI Model and can interpret MAC address. Information to determine whether to discard or form.
Transmission Control Protocol (TCP)
A core protocol of the TCP/IP suite that makes a connection with the end host, checks whether data is received and resends it if it is not.
TCP/IP
A suite od networking protocols that includes TCP, IP, UDP, and many more. Provides the foundations for data exchange across the internet.
Telnet
A terminal emulation protocol used to log on to remote hosts using the TCP/IP protocol.
Terminal Services
A feature of Windows server editions prior to Windows Server 2008 that allows technicians to manage remote applications.
Topology
How the part of a whole fit together.
Trailer
Control information attached to the end of a packet by the Data Link Layer protocol.
Transport Layer
The 4th layer of the OSI Model. Responsible for transporting application layer payloads from one application to another.
Trip Hazard
Items such as extension cords or tools lying on the ground in walkways that can cause someone to stumble.
User Datagram Protocol (UDP)
A core protocol in the TCP/IP suite that does not guarantee delivery because it does not first make the connection before sending data or check to confirm that data is received.
Unified Communication (UC)
The centralized management of multiple types of network-based communications: voice, video, fax, and messaging services.
Upset Failure
Damage that can shorten the life of a component and/or cause intermittent errors.
Video Teleconference (VTC)
An application that allows people to communicate in video and voice.
Voice Over IP (VoIP)
The provision of telephone services over a packet-switched network running the TCP/IP protocol suite.
Wide Area Network (WAN)
A network that spans a long distance and connects two or more LANs