Chapter3 Networking

Protocol

An agreed-upon set of rules and formats governing how devices structure, send, receive, and process data across a network.

Channel

The physical or wireless medium (copper wire, fiber optics, or radio waves) that provides the communication path between devices.

Encoding

The process of converting information into an acceptable pattern of electrical, optical, or radio signals for transmission over the channel.

Decoding

The process of reversing transmission signals back into interpretable data at the receiving host.

NIC (Network Interface Card)

The physical hardware component that connects devices to networks cable or wireless

TCP/IP Model

The four-layer network architecture powering the internet: Application, Transport, Internet, and Network Access.

Encapsulation

process of wrapping data with protocol information as it moves through network layers so it can be addressed, routed, transmitted, and verified.

De-encapsulation

process of removing headers from a data packet to reveal the actual data payload.

ARP (Address Resolution Protocol)

Resolves a known IPv4 address to its associated physical MAC address on the local network.

ICMP (Internet Control Message Protocol)

Sends diagnostic error reporting and operational feedback between hosts (the messaging protocol behind ping).

NAT (Network Address Translation)

Translates private local IPv4 addresses into globally routable public IPv4 addresses to communicate over the internet.

DNS (Domain Name System)

Translates human-readable domain names into numerical IP addresses.

DHCP (Dynamic Host Configuration Protocol)

Automatically and dynamically leases IP addresses, subnet masks, and network configurations to client devices at startup.

SMTP (Simple Mail Transfer Protocol)

Sends outbound email from a client to an email server, or between mail servers.

POP3 (Post Office Protocol version 3)

Retrieves and downloads email messages from a mail server directly onto a single client device.

IMAP (Internet Message Access Protocol)

Synchronizes and manages email messages stored centrally on the mail server across multiple client devices.

HTTP (Hypertext Transfer Protocol)

Delivers unencrypted web content (text, graphics, multimedia) between web browsers and web servers.

HTTPS (Hypertext Transfer Protocol Secure)

Delivers encrypted, authenticated web traffic using SSL/TLS encryption for secure communication.

FTP (File Transfer Protocol)

A reliable, connection-oriented, acknowledged protocol used for transferring files between hosts.

SFTP (SSH File Transfer Protocol)

An extension to Secure Shell (SSH) that provides encrypted, secure file transfers across a network.

TFTP (Trivial File Transfer Protocol)

basic file transfer with minimal overhead and no delivery acknowledgment.