NWT Chapter 1

Networking Today/Protocols and Models

• This chapter covers networking fundamentals, protocols, and models.
• The material is part of the Introduction to Networks v7.0 (ITN) course, Modules 1 and 3.

Topics and References

• Network Components: Section 1.2
• Network Representations and Topologies: Section 1.3
• Common Types of Networks: Section 1.4
• Internet Connections: Section 1.5
• Reliable Networks: Section 1.6
• Network Trends: Section 1.7
• Rules of Communication: Section 3.1
• Network Protocols and Standards: Section 3.2
• Protocol Suites: Section 3.3
• Standards Organizations: Section 3.4
• Reference Models: Section 3.5
• Data Encapsulation: Section 3.6

Network Components and Representations

• End devices (hosts): Devices where messages originate or terminate; can be a server or client (e.g., desktop computer, laptop, printer)
• Intermediate devices: Devices that regenerate and retransmit data, maintaining information about network paths (e.g., routers, switches)
• Network media: The medium allowing data transmission (e.g., copper wires, fiber optic, wireless)

Network Topologies

• Topology diagrams: Visual representations using symbols to depict devices and connections in a network
• Physical topology: Illustrates the physical location of devices and cable installation
• Logical topology: Depicts the addressing scheme of a network (devices, ports)

Types of Networks

• Local Area Network (LAN): A network within a home, building, or campus.
• Wide Area Network (WAN): A network that connects LANs across geographical distances.

Internet Connections

• Internet is an interconnection of networks (LANs and WANs).
• Internet Access Technologies: Methods to connect to the internet (e.g., dedicated leased line, Ethernet WAN, DSL, cable, satellite, cellular).

Reliable Networks

• Fault Tolerance: Ability to limit the impact of network failures, using redundancy to prevent single points of failure.
• Scalability: Ability to quickly expand the network to support new users, devices, and applications without affecting service delivery.
• Quality of Service (QoS): Providing different quality levels to different types of data; allows urgent data to take precedence over less critical data.
• Security: Physical and information security to protect devices and data from unauthorized access.

Network Trends

• Bring Your Own Device (BYOD): Trend of employees using their personal devices for work.
• Online collaboration: Working together on projects across geographical distances.
• Video: Using video conferencing for communication and collaboration.
• Cloud computing: Using remote servers to store and access data.

Rules of Communication

• Network protocols govern communication by establishing rules about how data is transmitted and received.
• Protocols act like grammar and sentence structure in human language.
• Protocol requirements include establishing a common language, sender/receiver identification, and speed/delivery timing.

Network Protocol Requirements

• Message encoding: Converting data into a suitable format for transmission.
• Message formatting and encapsulation: Structuring messages in a specific format for transmission.
• Message size, timing, delivery options: Ensuring suitable sizes, speed, and method of data delivery from sender to receiver.

Message Size and Timing

• Communication messages are segmented for ease of transmission and efficiency.
• Segment sizes are set with minimum and maximum limits, to meet the needs for various communications.
• Address information and encapsulation are added to segments to form a frame for transmission.
• Frame reception and interpretation relies on de-encapsulation.

Protocol Data Units (PDUs)

• Protocol Data Units refer to data units at each layer in a network stack (e.g., data in the application layer, segments in the transport layer, packets in the network layer, frames in the data link layer, bits in the physical layer).

Protocol Encapsulation and De-Encapsulation

• Encapsulation refers to the addition of header information to a data unit when moving it down a network layer stack.
• De-encapsulation refers to the removal of header information when moving data units up a network layer stack.

Different Ways for Message Delivery

• Unicast: One-to-one communication with a single destination.
• Multicast: One-to-many communication with multiple destinations.
• Broadcast: One-to-all communication with all possible destinations in the network.

Interaction of Protocols - Protocol Suite

• A protocol suite is a set of protocols working together to provide comprehensive network communication.
• TCP/IP Suite includes Application, Transport, Internet, and Network Access layers.
• These protocols work together to enable internet browsing (e.g., HTTP, TCP, IP).

Other Protocol Suites

• Other protocol suites (OSI, Apple Talk, Novell Netware) also exist.
• Each protocol suite offers its unique approach and functions, enabling a variety of networking capabilities.

Standards Organizations

• Standards organizations like the IEEE, IETF, ITU-T, and ICANN are involved in TCP/IP.
• Establish standards and promote vendor-neutrality in network communications.
• Their efforts contribute to overall network interoperability and innovation.

Reference Models

• Layered models (e.g., OSI and TCP/IP) aid in network design and are important in understanding networking operations.
• Assist in protocol design and ensure a defined layer interface.
• Implement cross-layer communication and fostering competition.

Data Encapsulation

• Messages are segmented and encapsulated during transmission and de-encapsulated when received.
• Advantages include interleaved conversations and reliability.
• Disadvantages include increased complexity.
• Sequencing is included to reassemble message segments correctly, at the destination..