Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are two primary transport-layer protocols used in internet communication. TCP is a connection-oriented protocol that ensures reliable and accurate data delivery between devices by establishing a connection, retransmitting lost segments, and acknowledging received data. It provides flow control and congestion management, making it suitable for applications like file transfers or web browsing. On the other hand, UDP is a connectionless and faster protocol with no guarantee of data delivery. It is used in applications where real-time performance is more critical than reliable data delivery, such as Voice over IP (VoIP), online gaming, and video streaming.

Routing and switching are core components of any network architecture responsible for managing data flow, connectivity, and network communication. Switching involves moving data packets between devices within a local area network (LAN) using MAC addresses, working at the data link layer (layer 2) of the OSI model. Switches maintain MAC address tables to efficiently forward packets to the intended destination device. Routing, on the other hand, oversees the path selection and delivery of data packets between networks or subnets, operating at the network layer (layer 3) of the OSI model. Routers use routing tables and routing protocols to determine the best route for data packets to traverse, ultimately directing traffic to the appropriate destination network.

Network cabling and transmission play a critical role in transferring data between devices on a network. There are various types of cables and transmission methods used, such as copper cables (coaxial, twisted-pair), fiber-optic cables, and wireless transmission (radio frequencies, infrared, and microwave). Copper cables are the most widely-used medium for data transmission, whereas fiber-optic cables offer better bandwidth, distance, and reliability. Wireless transmission methods eliminate the need for physical cables, allowing for mobility and ease of deployment. Selection of the appropriate cabling and transmission method depends on factors such as speed, distance, cost, security, interference, and environmental constraints.

IPv4 and IPv6 addressing are methods used to assign unique numerical identifiers to devices on a network. IPv4 is the fourth version of the Internet Protocol and uses 32-bit addresses, resulting in roughly 4.3 billion possible unique addresses. As the number of devices connected to the internet has increased, IPv4 addresses have become more limited. IPv6, the successor to IPv4, uses 128-bit addresses, providing a significantly larger pool of unique addresses, making it better suited for the growing number of connected devices. In addition to the expanded address space, IPv6 also introduces improvements in routing and network configuration. Both IPv4 and IPv6 are used in the real world, with IPv6 adoption steadily increasing as the demand for more IP addresses grows.

WAN Technologies refers to the various methods and protocols used to connect geographically distant networks across Wide Area Networks (WANs). WANs are networks that span over large areas, like cities, states, or countries. Several key WAN technologies are employed to establish these connections, such as leased lines (dedicated point-to-point circuits), ISDN (Integrated Services Digital Network), Frame Relay (a packet-switching technology), MPLS (Multiprotocol Label Switching, used for routing decisions), and VPN (Virtual Private Network, which creates a secure and encrypted connection across the internet). Being knowledgeable about WAN technologies is essential for network professionals to properly design, monitor, and maintain remote network connections.