D481 OA Terminology

TCP/IP application protcols

DHCP HTTP IMAP FTP POP SIP

OSI Transport Layer Devices

Gateway, firewall

OSI Application Layer Devices

Gateway, firewall, endpoint device (server, PC, mobile device, etc.)

OSI Presentation Layer Devices

Gateway, firewall, server, PC

OSI Session Layer Devices

Gateway, firewall, server, PC

TCP/IP Network or Internet Layer 2

Handles the routing of packets as they move around the network. It maps to Layer 3 of the OSI model.

OSI Physical Layer Devices

Hub, repeater, cable, fiber, wireless

OSI Network Layer Protocols

ICMP, IGMP, IGRP, IPv4, IPv6, IPSec, IPX, GRE, OSPF, RIP

TCP/IP Internet Layer Protocols

ICMP, IPSEC

OSI Session Layer Protocols

L2F, L2TP, NetBIOS, NFS, RPC, SMB, SSH

Mesh

Multipoint connections and direct links between network devices

IANA (Internet Assigned Numbers Authority)

Organization responsible for assigning IP addresses to public networks.

TCP/IP Transport or Host-to-Host Layer 3

Provides end-to-end delivery, which maps to OSI Layer 4. This layer segments the data and adds a checksum to properly validate data to ensure that it has not been corrupted.

TCP/IP Physical or Network Access Layer 1

Resides at the lowest layer of the TCP/IP model and is the point at which the higher-layer protocols interface with the network transport media. When compared to the OSI model, this layer corresponds to OSI Layer 1 and Layer 2.

OSI Application Layer 7

Responsible for interacting with end users. This Layer includes all programs on a computer that interact with the network; for example, your email software is included because it must transmit and receive messages over the network. A simple game like Solitaire doesn't fit here because it does not require the network to operate.

OSI Network Layer Devices

Router, brouter, Layer 3 switch

Circuit Switched Network

Sets up a path between the source and destination devices. The two devices use the same path, or circuit, throughout the conversation. This is the model the original analog telephone system used. Implemented at the physical layer

Most common TCP/IP Transport Layer Protocols

TCP UDP

TCP/IP Application Layer 4

The top of the TCP/IP Reference Model, which maps to OSI Layers 5, 6, and 7. This interacts with applications that need to gain access to network services.

OSI Transport Layer 4

This is responsible for breaking data into packets and properly transmitting them over the network. Flow control and error checking take place here. TCP operates in this layer

OSI Session Layer 5

This is responsible for maintaining communication sessions between computers. This Layer creates, maintains, and disconnects communications that take place between processes over the network.

OSI Presentation Layer 6

This is responsible for the coding of data. This Layer includes file formats and character representations. From a security perspective, encryption generally takes place at this layer.

OSI Network Layer 3

This is responsible for the logical implementation of the network. One important feature of this Layer is logical addressing. In TCP/IP networking, logical addressing takes the familiar form of IP addresses. IPs operate in this layer.

OSI Physical Layer 1

This is responsible for the physical operation of the network. This Layer must translate the binary ones and zeros of computer language into the language of the transport medium. In the case of copper network cables, it must translate computer data into electrical pulses. In the case of fiber optics, it must translate the data into bursts of light.

OSI Data Link Layer 2

This is responsible for transmitting information on computers connected to the same local area network (LAN) . The Data Link Layer uses Media Access Control (MAC) addresses. Device manufacturers assign each hardware device a unique MAC address.

Transmission Control Protocol/Internet Protocol (TCP/IP) Suite

a collection that provides support to nearly all internet-capable operation systems and devices

Transmission Control Protocol/Internet Protocol (TCP/IP) Reference Model

a descriptive framework for computer network protocols, created by the U.S. Department of Defense in the 1970s

network topology

a map of a network and how devices are connected to it

point-to-point network

a network that consists only of computers and devices that are connected directly

circuit-switched

a network that creates a path between the source and destination devices

Real-time communication

a networking paradigm where data is transmitted and received instantly, with minimal delay. It is essential for applications that require immediate and predictable delivery of information, such as voice and video calls, online gaming, and live streaming.

Store and Forward Communication

a networking technique where data is received, stored briefly in its entirety, and then forwarded to the next node in the network. The entire message is stored before being transmitted, allowing for error checking and retransmission if necessary.

extranet

a private network that allows authorized external users to securely share information

intranet

a private, internal network

Open Systems Interconnection (OSI) Reference Model

an internationally accepted framework of standards that governs how separate computer systems communicate using networks

Internet Protocol (IP) Suite

another name for the TCP/IP suite

packet-switched

networks that transmit packets as individual messages

Transmission Control Protocol (TCP)

part of the TCP/IP that guarantees a reliable stream of data between two computers

Internet Protocol (IP)

part of the TCP/IP that make it possible to deliver packets across complicated networks by handling the routing decisions necessary to move them from their source to their destination

logical topology

shows how the devices in a network connect to a specific segment of the network

physical topology

the physical network devices and any physical devices used to connect to the network

internetworking

the process of connecting multiple computer networks

Packet-Swtiched Network

utilized for digital communication and implemented at the network layer.

Point-to-point

A direct link or connection between two devices

Bus Network Topology

A shared network transmission medium allowing only one device to communicate at a single time

Ring Network Topology

A shared ring connecting multiple devices together

Star Network Topology

A star-wired connection aggregation point, typically from a wiring closet

OSI Presentation Layer Protocols

AFP, SSL, TLS

OSI Transport Layer Protocols

AH (over IP/IPSec), BGP, ESP (over IP/IPSec), TCP, UDP, SPX

OSI Data Link Layer Protocols

ARP, Ethernet (IEEE 802.3), FDDI, Frame Relay, IND, L2TP, PPP, MAC, NPD, RARP, STP, Token Ring, VLAN, Wi-Fi (IEEE 802.11), WiMax (IEEE 802.16), X.25

TCP/IP Network Access Layer Protcols

ARP, L2TP, PPP, DSL, FDDI

Hybrid/star-wired bus

Also known as a tree topology; a shared, star-wired connection aggregation point to a LAN switch

OSI Application Layer Protocols

BitTorrent, DNC, DSNP, DHCP, FTP, HTTP(S), IMAP, MIME, NNTP, NTP, POP3, RADIUS, RDP, SMTP, SOAP, Telnet

OSI Physical Layer Protocols

Bluetooth, DSL, Ethernet (Physical Layer), USB, Wi-Fi (Physical Layer)

OSI Data Link Layer Devices

Bridge, modem, network card, Layer 2 switch

Plain Old Telephone Service (POTS) or Public Switched Telephone Network (PSTN)

Carries analog signals. These analog communications work well on circuit-switched networks because the messages are continous.