ITS124 Sections 1-13

Network

An assortment of at least two connection points, or nodes, capable of sharing technology resources via a link.

Node

A connection point on a network, such as a computer, laptop, smartphone, or a piece of networking equipment.

Link

The network medium connecting network nodes (can be wired, wireless, or both).

Topology

Identifies how nodes in a network are arranged.

Single Point of Failure (SPOF)

A critical business resource without redundancy and diversity.

Bandwidth

The maximum amount of data a connection can transmit in a given amount of time.

Redundancy

The duplication of a business resource to eliminate a SPOF.

Physical Topology

Documentation identifying how network nodes are physically arranged.

Logical Topology

Documentation identifying how network nodes are configured for communication.

Bus Topology

A physical topology where network nodes are connected to a single cable or bus.

Ring Topology

A physical topology where each node is connected to exactly two other nodes, resembling a ring.

Star Topology

A physical topology where each node is connected to a central node, resembling a star or a hub with spokes.

Mesh Topology

A physical topology where each node is connected to every other node in a network.

Hybrid Topology

A physical topology where at least two different physical topologies are combined (e.g., a star-bus topology).

Packet-Switched Network (PSN)

A network where the network parts, or planes, are configured to break down data into smaller pieces, or packets, for transmission using any available link.

Circuit-Switched Network

A network that uses preconfigured links from source to destination, where the physical and logical topologies reflect each other.

Control Plane

The network plane that determines how a packet is transmitted (relies on communication standards or protocols).

Data Plane

The network plane that transmits a packet (relies on information from the control plane, like routes and addresses).

Management Plane

The network plane that manages and monitors the nodes used in the control and data planes.

Bounded Media

A network medium using cabling (such as coaxial, twisted pair, or fiber) to transmit data through a narrow, or bounded, communication path. Typically used in wired networks.

Unbounded Media

A network medium using a wireless signal (such as infrared, radio frequency, or Bluetooth) to transmit data through an open, or unbounded, space. Typically used in wireless networks.

Client

A node that accesses a network resource from a server, but does not share network resources with other clients.

Server

A node that shares a network resource with a client.

Peer

A node capable of sharing and accessing a network resource with other peers.

Peer-to-peer (P2P) model

A network model consisting of peer nodes that share and access network resources from each other.

Client-server model

A network model consisting of at least one server that shares a network resource with at least one client.

Personal area network (PAN)

A small, single-location network for a single user and the user's personal networked devices.

Local area network (LAN)

A small, single-location network for multiple users and multiple networked devices.

Wireless LAN (WLAN)

A LAN consisting of networked devices communicating by unbounded media.

Metropolitan area network (MAN)

A large, multilocation network connecting at least two single-location networks for a city or municipality.

Campus area network (CAN)

A large, multilocation network connecting at least two single-location networks for a school or corporate campus.

Wide area network (WAN)

A large, multilocation network connecting at least two single-location networks from different geographic areas.

Overlay network

A virtual network abstraction layer built on top of an existing physical network infrastructure.

Underlay network (Transport network)

The underlying physical transport network required for the deployment of an overlay network.

Multiprotocol label switching (MPLS)

An overlay network technology that labels each data packet and uses the label to find the quickest path to the data packet's destination.

Multipoint generic routing encapsulation (MGRE)

An overlay network technology that forms a point-to-multipoint tunnel to carry multiple protocols and traffic types over a single link.

Software-defined networking (SDN)

An overlay network technology that centralizes a single-location network's management and control planes.

Virtual extensible LAN (VXLAN)

An overlay network technology that extends the capabilities of a locally-switched network over routed networks to improve network conditions among dedicated computing facilities.

Service provider

A vendor who provides telecommunications services, such as telephone or internet services.

Service-related entry point

The location where a service provider's medium enters a customer's premises (e.g., a basement in an office building or a leasing office).

Demarcation point (demarc)

The exact location where a service provider's equipment connects to a customer's on-premise equipment.

Smartjack

A network interface device (NID) placed in a demarcation point to provide remote monitoring and other capabilities to a service provider.

Copper

A bounded media consisting of a copper core carrying electrical pulses.

Fiber

A bounded media consisting of glass or plastic strands carrying light pulses.

Digital subscriber line (DSL)

A telecommunications service delivering high-speed internet access using existing telephone infrastructure. It is often used as a backup internet service for businesses.

Cable

A shared telecommunications service delivering high-speed internet access using existing cable television infrastructure.

Satellite

A telecommunications service delivering high-speed internet access using low-earth orbit (LEO) satellites and a dish at a customer's location, most commonly used in rural areas where deploying other infrastructure isn't cost-effective.

Leased line

A telecommunications service delivering high-speed internet access using a customer-specific, dedicated leased connection between two sites.

Metro-optical

A generic term for a telecommunications service delivering high-speed internet access using fiber, recognizing how service providers in metropolitan areas have transitioned from copper.

Conceptual model

A representation of a system or a process, used in networking to help understand end-to-end network communication.

Open Systems Interconnection (OSI) model

A seven-layer network conceptual model created by the International Organization for Standardization (ISO).

Department of Defense (DoD) model (or TCP/IP model)

A four-layer network conceptual model implemented as the internet protocols suite.

Abstraction layer

A generalization of a system, process, or device. The OSI model abstraction layers classify network devices, while the DoD model abstraction layers describe network protocols.

Network protocol

A set of rules specifying how data is formatted, processed, and transmitted between devices on a network.

Encapsulation

The process of adding a header or trailer so data is transmittable.

Header

An information field added before a piece of data before transmission.

Trailer

An information field added to the end of data before transmission.

Protocol data unit (PDU)

Data encapsulated with an abstraction layer's header or trailer.

Payload

The actual data being transmitted, which excludes the headers or trailers added by each abstraction layer.

Decapsulation

The process of removing a header or trailer so data is receivable.

Application layer (Layer 7)

The OSI model layer where a network protocol interacts with a network-aware application.

Presentation layer (Layer 6)

The OSI model layer where data is prepared for transmission between the application layer and session layer.

Session layer (Layer 5)

The OSI model layer where a data transmission channel known as a session is established between communicating devices.

Session

A data transmission channel established between communicating devices.

Transport layer (Layer 4)

The OSI model layer where data from the upper-level layers is divided into smaller-sized blocks of data for faster transmission.

Transmission control protocol (TCP)

A network protocol used to establish a guaranteed, connection-oriented communication channel between communicating devices.

User datagram protocol (UDP)

A network protocol used to provide non-guaranteed, connectionless data transport for communicating devices.

Segment

The protocol data unit (PDU) created by TCP, which includes a TCP header consisting of connection state information known as a TCP flag.

TCP flag

Connection state information included in a TCP header.

Datagram

The PDU created by UDP, which includes a UDP header.

Network layer (Layer 3)

The OSI model layer where data receives logical address information needed to reach the recipient's network.

Internet protocol (IP)

The network protocol used to address data sent over the internet or another network.

Packet

The PDU created by IP, which includes an IP header consisting of logical address information.

Router

A layer 3 networking device connecting at least two networks.

Routing protocol

A network protocol used by a router to determine the most efficient route to a destination network.

Data link layer (Layer 2)

The OSI model layer where data is transmitted to the recipient node.

Frame

The PDU created by layer 2 containing data transmission parameters and physical address.

Logical link control (LLC)

A layer 2 sublayer providing data flow control, error detection, and error correction.

Media access control (MAC)

A layer 2 sublayer providing physical address and frame synchronization.

Switch

A layer 2 networking device serving as a central node for at least two other nodes.

Physical layer (Layer 1)

The OSI model layer where a payload is transmitted across a network medium.

Radio wave

Artificially generated energy that radiates electrical current into open space.

Binary number

A number expressed in a base-2 numeral system.

Bit (Binary digit)

A single digit in a binary number, represented as a zero or one.

Application layer

The DoD model's highest layer, where a network-aware application interacts with transmitted data.

Transport layer

The DoD model layer where end-to-end payload delivery from source to destination occurs.

Port number (or port)

A 16-bit unsigned number that uniquely identifies a network application or service on a host.

TCP header

A 10-field, 20-byte header containing connection and payload delivery details for a segment.

UDP header

A 4-field, 8-byte header containing connection and payload delivery details for a datagram.

Internet layer

The DoD model layer where hop-to-hop data delivery from source to destination occurs.

IP header

A header containing connection and payload delivery details for a packet.

IP version 4 (IPv4)

The fourth version of IP, which provides internetworking capabilities on the internet and packet-switched networks.

IP version 6 (IPv6)

The sixth version of IP, which provides internetworking capabilities on the internet and packet-switched networks.

IPv4 header

A 14-field, 20- to 60-byte header containing connection and payload delivery details for an IPv4 packet.

IPv4 address

A unique 32-bit numeric address divided into four 8-bit octets.

IPv6 header

An 8-field, 40-byte header containing connection and payload delivery details for an IPv6 packet.

IPv6 address

A unique 128-bit number assigned to a network interface controller.

Network access layer

The DoD model layer where data transfer between two devices on the same network occurs.

Institute of Electrical and Electronics Engineers (IEEE)

A professional organization that advances technology through technical standard development and other efforts.