Networking Concepts

Network Protocols and Their Functions

• Network protocols enable network operations, defining how messages are formatted, delivered, and handled across networks.
• Network communication processes describe the basic operation of data networked communications.
• Data encapsulation is the embedding of data within other pieces of data for transportation across the network.
• Peer-to-peer networks involve computers acting as both servers and clients within a network.
• Small home networks connect a few computers together and to the internet.
• Small office or home office (SOHO) networks allow home offices and remote offices to connect to corporate networks accessing centralized, shared resources.
• Medium to large networks are used by corporations and schools, often with numerous locations, thousands of hosts, and interconnected network devices.
• Worldwide networks (the internet) connect millions of computers or devices globally.
• Hosts are computers directly connected and actively involved in network communication.
• Servers are computers with specialized software enabling them to provide information to other devices on the network.
• Single-purpose servers deliver a specific service (e.g., a web page).
• Multipurpose servers provide various services (e.g., web pages, email, file transfers).
• Client computers request and display information from servers using software enabling this interaction.
• File servers store corporate and user files centrally accessible to client devices with software.
• Web servers operate web server software accessible via client browsers.
• Email servers use email server software accessed using email client software.
• Typical network sessions involve users establishing many connections using various computing devices.
• Wi-Fi networks enable devices to connect to the internet and other network resources wirelessly.
• Search engines allow users to find information online using software systems designed to perform web searches.
• Search submissions occur wirelessly from devices to a network to allow for searching across networks.
• Search addressing directs search data to enable the return of the results to the user device.
• Search string encoding converts binary data into radio waves and electrical signals for network transmission.
• Search engine processing involves technologies that process search requests.
• Search results encoding addresses search results to their respective destinations.
• Gaming console connections use an ISP (Internet Service Provider) with a router and cable modem.
• Cable network connections allow home networks to connect to cable TV networks belonging to the same ISP as well as other devices in the neighborhood through a fiber optic network.
• Gaming data transmissions occur when a gaming console connects to an online gaming company.
• Game data identification adds information to game data, such as player details, the game, and network location.
• High-speed data transmission is done at a high speed.
• Game results return graphics and sounds to the player to show the results of their game actions.
• Cloud services for medical data allow storage of medical data such as X-rays accessible over the internet.
• X-ray data digitization turns medical images into digital data.
• Hospital network encryption encrypts data and prevents interception.
• Data center routing directs data to appropriate facilities and services on the cloud.
• Digital interaction in healthcare occurs through networked digital services.
• Cybersecurity analysts use deep understanding of network operations to protect data and systems.
• Data transmission cables are used to carry data over land/ocean (copper/fiber-optic).
• Tier 1 and Tier 2 ISP connections connect networks using internet exchange points (IXPs).
• Point of presence (PoP) locations establish connections between larger networks and Tier 2 networks.
• Tier 3 ISPs connect homes and businesses to the internet using local networks.
• Traceroute utilities examine network pathways.

Network protocols (lab objectives), traceroutes, and basic networking concepts, protocols

• Lab objectives use utilities to examine network pathways to specified destinations.
• Traceroute utility uses command lines or web-based tools to trace pathways.
• Protocols govern communication between devices.
• Network protocols enable communication between computers on a network.
• Message encoding specifies how messages are formatted for transmission.
• Message formatting determines the structure of messages.
• Encapsulation wraps data with protocol information.
• Message size specifies the allowable size of messages.
• Timing defines message delivery timing and acknowledgments.
• Delivery options specify message delivery methods.

Network Protocols, Models, and Implementation

• Hypertext Transfer Protocol (HTTP) transfers hypertext requests.
• Transmission Control Protocol (TCP) ensures reliable data transmission.
• Internet Protocol (IP) handles data addressing and routing.
• IPv4 (version 4) and IPv6 (version 6) are internet protocols for addressing data.
• Message structure specifies message formatting.
• Path sharing enables network communication path information sharing.
• Session management controls session setup and termination.
• Information sharing governs error and system message exchanges.
• TCP/IP protocol suite is the internet's core communications protocol.

Open Standard Protocols

• Open standard protocols are freely available protocol suites.
• Standard-based protocols have industry endorsements.
• Domain Name System (DNS) translates domain names to IP addresses.
• Dynamic Host Configuration Protocol (DHCPv4/v6) dynamically assigns IP addresses.
• SLAAC uses a method without a DHCPv6 server to obtain addresses.
• SMTP enables client email sending to a server.
• POP3 allows clients to retrieve email from a server.
• IMAP enables client access and maintenance of stored server email.
• FTP specifies rules for file transfer.
• SFTP provides secure file transfer using encryption.
• Secure Shell File Transfer Protocol (SFTP) uses secure file transfer sessions employing encryption.

Further Network Protocols

• Trivial File Transfer Protocol (TFTP) is a simple connectionless protocol for file delivery.
• Hypertext Transfer Protocol (HTTP) defines text, image, sound, video, and multimedia file exchange rules

HTTP extensions and web services

• HTTPS enhances HTTP with encryption.
• REST (Representational State Transfer) uses APIs and HTTP for web apps.

Communication protocols (TCP, UDP, IP versions)

• TCP (Transmission Control Protocol) ensures communication between hosts.
• UDP (User Datagram Protocol) allows one host to send packets to another.
• IPv4 is a 32-bit addressing protocol; IPv6 is a 128-bit addressing protocol; Network Address Translation (NAT) handles translations of addresses.

Routing and Addressing Protocols

• Internet Control Message Protocol (ICMPv4/v6) provides feedback on errors for source hosts.
• Internet Control Message Protocol Version 6 (ICMPv6 ND) enables detection of duplicate addresses.
• Open Shortest Path First (OSPF) is a link-state routing protocol.
• Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco propriety routing protocol.
• Border Gateway Protocol (BGP) is an exterior gateway routing protocol.
• Address Resolution Protocol (ARP) maps IPv4 addresses to hardware addresses.
• Ethernet and Wireless Local Area Networks (WLANs) define wiring and signaling standards.

Network Layer Concepts

• Message formats depend on the message type.
• Data encapsulation involves placing one message format in another.
• Decapsulation reverses the process; Internet Protocol (IP) is responsible for sending messages across networks.
• Messages are sometimes broken into smaller parts, and flow control manages how much information is sent, along with speed.
• Response timeouts define how long to wait for responses; different access methods apply in different network contexts.
• Unicasting, multicasting, and broadcasting refer to message delivery methods.
• Different layered models, such as the Open Systems Interconnection (OSI) model and the TCP/IP model, describe network operations using layers.

Further Network Layer Details

• Data Link Layer and Physical Layer (OSI) specify data transfer between devices.
• Application Layer (TCP/IP) formats data for user interaction.
• Transport Layer (TCP/IP) manages communication across diverse networks.
• Internet Layer (TCP/IP) determines the optimal network pathways.
• Network access layer controls hardware for data transmission.
• Segmentation divides data into smaller parts, improving efficiency.
• Multiplexing allows multiple conversations to occur simultaneously.
• Sequencing ensures each transmission segment reaches its correct destination.
• Protocol data units (PDUs) use various protocols, and encapsulation adds protocol information during transmission.
• Specific PDU names reflect their functions (eg, UDP PDU or IP Packet).

Client-Server Communication, Encapsulation, and Special Tools

• Client-server communication requires three address levels (transport, network, and data link)
• Encapsulation details show how upper-layer information is treated as data in encapsulation processes.
• Wireshark is used in various contexts (e.g. protocol analysis)
• Many network protocols provide features of communication (messages).
• OSI and TCP/IP models describe network layers.
• Segmentation breaks messages into parts for transmission and improves efficiency.
• Multiplexing enables simultaneous conversations.
• Sequencing method helps ensure message segments reach their destinations.

Test your knowledge of networking concepts, covering topics such as client-server interactions, network protocols, and data transmission. Explore the functions of various servers and network types. Understand the processes involved in online search and data communication.