Networking Glossary

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A

✏️ ARP

Address Resolution Protocol

B

C

D

✏️ DHCP

Dynamic Host Configuration Protocol

E

F

G

H

I

✏️ IP

Internet Protocol

✏️ ISO

International Organization for Standardization

J

K

L

✏️ LAN

Local Area Network

M

✏️ MAC address

Media Access Control address or Medium Access Control address is a unique identifier assigned to a network interface controller for use as a network address in communications within a network segment. It is usually expressed in hexadecimal format with colons or hyphens separating the bytes (e.g., a4:c3:f0:85:ac:2d), sometimes there is no separator. The three leftmost bytes identify the vendor (in the previous example a4:c3:f0 identifies Intel).

N

O

✏️ OSI model

The Open Systems Interconnection model is a conceptual model developed by ISO that describes how communications should occur in a computer network, i.e., it defines a framework for computer network communications. Although this model is theoretical, it is vital to learn and understand as it helps grasp networking concepts on a deeper level. The OSI model is composed of seven layers:

Physical Layer (Layer 1)

Main function: physical data transmission media

Example Protocols and Standards: electrical, optical and wireless signals

Data Link Layer (Layer 2)

Main function: reliable data transfer between adjacent nodes

Example Protocols and Standards: Ethernet (802.3), WiFi (802.11)

Network Layer (Layer 3)

Main function: logical addressing and routing between networks

Example Protocols and Standards: IP, ICMP, IPSec

Transport Layer (Layer 4)

Main function: end-to-end communication and data segmentation

Example Protocols and Standards: UDP, TCP

Session Layer (Layer 5)

Main function: establishing, maintaining and synchronising sessions

Example Protocols and Standards: NFS, RPC

Presentation Layer (Layer 6)

Main function: data encoding, encryption and compression

Example Protocols and Standards: Unicode, MIME, JPEG, PNG, MPEG

Application Layer (Layer 7)

Main function: providing services and interfaces to applications

Example Protocols and Standards: HTTP, FTP, DNS, POP3, SMTP, IMAP

P

Q

R

S

T

✏️ TCP

Transmission Control Protocol is a connection-oriented transport protocol. It uses various mechanisms to ensure reliable data delivery sent by the different processes on the networked hosts. It is a layer 4 protocol. Being connection-oriented, it requires the establishment of a TCP connection before any data can be sent.

✏️ TCP/IP

Transmission Control Protocol/Internet Protocol or Internet protocol suite is an actual implemented model.

✏️ Telnet

Teletype Network protocol is a network protocol for remote terminal connection. Simply put, telnet, a TELNET client, allows you to connect to and communicate with a remote system and issue text commands.

U

✏️ UDP

User Datagram Protocol is a simple connectionless protocol that operates at the transport layer, i.e., layer 4. Being connectionless means that it does not need to establish a connection. UDP does not even provide a mechanism to know that the packet has been delivered.

V

W

X

Y

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