Network Communication Protocols Explained

Rules of Communication

• Protocols are rules that ensure data is transmitted accurately and efficiently across a network.
• Protocols enable different devices and systems to understand each other in a network.

TCP/IP

• TCP/IP (Transmission Control Protocol/Internet Protocol) is a model with protocols for internet communication.
• TCP ensures reliable data delivery.
• IP handles addressing and routing.

Network Protocols and Standards

• Network protocols are rules that govern data communication.
• The International Organization for Standardization (ISO) and the Institute of Electrical and Electronics Engineers (IEEE) are standards organizations.
• Standards organizations establish protocols to ensure different devices and systems work together seamlessly.

Data Transfer in the Network

• Data transfer involves sending data in small units called packets.
• Packets are routed through network nodes until they reach their destination.
• Packet switching and routing are key concepts in the process.

Internet, Intranet, Extranet

• Internet is a global network accessible to anyone with an internet connection.
• Intranet is a private network accessible only to an organization's members.
• Extranet is a controlled private network allowing limited access to external users.

OSI Layer

• The OSI (Open Systems Interconnection) model standardizes telecommunication or computing system functions into seven layers.
• Each layer has specific functions and communicates with the layers above and below it.
• It is a conceptual framework.

OSI Model

• Open Systems Interconnection is known as OSI.
• The International Standard Organization (ISO) adopted the architectural OSI model in 1977 in Geneva, Switzerland.
• The name "isos" is derived from the Greek word meaning equal.
• The OSI model is an abstract description for layered communications and computer network protocol design.

Application Layer

• The application layer provides network services directly to end-user applications.
• User interface is enabled via various protocols.
• Examples are HTTP, FTP, and SMTP.

Presentation Layer

• The presentation layer translates data between the application layer and the network.
• Tasks such as data encryption, compression, and translation are handled.
• SSL/TLS, JPEG, and MPEG are some examples.

Session Layer

• The session layer manages sessions or connections between applications.
• Establishing, maintaining, and terminating connections ensures proper data exchange.
• Network File System (NFS) and SQL sessions are examples.

Transport Layer

• The transport layer ensures complete data transfer between end systems.
• It provides error checking, flow control, and retransmission of lost data.
• Examples include TCP and UDP.

Network Layer Protocols

• This layer routes data packets to their destination including IP, routers.
• Protocols handle the logical addressing and routing of packets.

Data Link Layer Protocols

• Establishing, maintaining, and terminating the physical link between devices is handled by the data link layer.
• Error detection and correction are ensured.

Media Access Control (MAC)

• MAC addresses are unique identifiers assigned to network interfaces for communication on the physical network segment.
• MAC addresses ensure data is sent to the correct recipient.

IP Address

• IP addresses identify a device globally on the internet or across different networks.
• It can be assigned dynamically and operates at the network layer.
• IP address ensures the data reaches the correct network or device across broader networks.
• The MAC address ensures data reaches correct device w/in the local network.

Physical Layer Protocols

• The physical layer is responsible for the physical connection between devices.
• Hardware like cables, switches, and physical media are included in the physical layer.

Network Media

• Network media are the physical pathways that connect computers, devices, and people on a network.
• Different media types have different characteristics, such as speed and capacity.

Classification of Network Media

• Wired media, such as bounded, cabled, conducted, or guided media, uses physical cables like copper or fiber-optic cables.
• Wireless media, such as unbounded or radiated media, is unguided and relies on electromagnetic waves like radio waves or microwaves.

Characteristics of Copper Media

• Data is transmitted over copper cables in the form of electrical pulses.
• Attenuation is the gradual weakening and deterioration of signals as they travel over copper cables, necessitating distance limitations.
• Shielding is often used to wrap copper cables and protect the signals from external interference (EMI and RFI).
• Crosstalk reduction is achieved via twisted pairs of wires where opposing circuit wire pairs are twisted together.

Characteristics of Digital Signals

• Pure Digital Signals have clear, distinct values over time and typically have two states: high and low.
• Interference Signals cause noise or disturbances on the signal.
• Common interference sources are electromagnetic interference and radio frequency interference.
• Digital Signals with Interference is when a pure digital signal is distorted by interference.
• Signal integrity is compromised and it is harder to distinguish between high and low states.
• What the computer reads (Changed Signal) represents the signal after the computer attempts to interpret the distorted signal.
• Error detection and correction techniques reconstruct the original signal as accurately as possible.

Factors to Consider When Choosing Network Media

• Cost: The overall expense of the media, including installation and maintenance.
• Ease of Installation: The complexity and effort required to install the media.
• Flexibility: The ability of the media to adapt to different environments and configurations.
• Resistance to Interference or EMI (Electromagnetic Interference): The media's ability to withstand external interference that can distort or corrupt data signals.
• Speed, Capacity, or Bandwidth: The amount of data that can be transmitted over the media in a fixed amount of time.
• Attenuation: The extent to which the signal weakens as it travels over distance.

Types of Wired Media

• Copper twisted pair
• Copper coaxial cable
• Optic fiber cable

Twisted Pair (TP) Cable

• Data is carried in the form of electronic signals.
• Construction consists of two insulated strands of copper wire.
• Speed and throughput is 10-100 Mbps
• Max cable length is 100m

Types of Twisted Pair Cables

• Shielded Twisted Pair (STP) cables have an additional covering like foil or braided shield around the wire pairs.
• Enhanced protection against electromagnetic interference (EMI) and crosstalk is provided.
• Signal quality in electronic device environments is maintained.
• Unshielded Twisted Pair (UTP) cables lack the shielding found in STP cables.
• Twisting of the wire pairs reduces interference and crosstalk.
• Commonly used in networking due to their lower cost, flexibility, and ease of installation.

Advantages of Twisted Pair Cables

• Availability and cost: they are widely available and relatively inexpensive
• Ease of installation: easy to install, making them a practical choice for networking scenarios.
• Spatial efficiency: These cables offer excellent spatial efficiency, providing high transmission capacity in a compact form.
• Information-carrying capacity: Up to 1 Gigabit per second over distances of 100 meters.
• Application independence: versatile and can be used for a wide range of applications.

Disadvantages of Twisted Pair Cables

• Transmission rates for long distances: Relatively low versus fiber optics.
• Unsuitability for high-speed data transmission: They are not ideal for very high-speed requirements.
• Susceptibility to interference: Prone to signal distortion or errors from electromagnetic interference (EMI) and crosstalk.

Different Ethernet Cable Categories

• Category 1 (CAT 1): Supports data transmission of up to 1 Mbps and is used for voice communication.
• Category 2 (CAT 2): Supports data transmission of up to 4 Mbps and is used in older token ring networks.
• Category 3 (CAT 3): Supports data transmission of up to 10 Mbps is commonly used in telephone wiring and older 10BASE-T Ethernet networks.
• Category 4 (CAT 4): Supports data transmission of up to 16 Mbps and is used in older token ring networks but is now obsolete.
• Category 5 (CAT 5): Supports data transmission of up to 100 Mbps and is used for 100BASE-TX Ethernet networks.
• Category 5 Enhanced (CAT 5e): Supports data transmission of up to 1000 Mbps (Gigabit Ethernet) and reduces crosstalk compared to CAT 5.
• Category 6 (CAT 6): Supports data transmission of up to 10 Gbps (Gigabit Ethernet) over short distances (up to 55 meters).
• Stringent specifications for crosstalk and system noise are more so than CAT 5e.
• Category 7 (CAT 7): Supports data transmission of up to 10 Gbps over 100 meters of copper cabling.

Twisted Pair Connectors

• Tera connector- standard interface for Category 7/Class F and broadcast communications technology (BCT) cabling
• RJ 45 - Registered Jack - Type 45 Electrical connector used for terminating twisted pair type cables.
• RJ11- Physical interface used for terminating telephone wires.

Coaxial Cable

• Carries data in the form of electrical signals.
• Contains a center wire surrounded by insulation and then a grounded shield of braided wire

Two Basic Types of Coaxial Cable

• Thin coaxial cable (thin coax Or RG (Radio Guide)-58) that is about 0.64 centimeters/0.25 inch in diameter.
• Attenuation of the cable is 185 meters, rounded off to 200 at times.
• Thick coaxial cable (thick coax or RG (Radio Guide)-8) that is about 1.25 centimeters/0.5 inch in diameter.
• Attenuation of the cable is 500 meters.

Coaxial Cable Advantages and Disadvantages

• Advantages: better immunity to interference, reasonable cost at short distances, standards and technology are mature, and heavy cable is very durable.
• Disadvantages: lack of security, lower data transmission rates, and must be kept dry or it will lead to leakage

Fiber Optic Cable

• Carries data in the form of modulated pulses of light.
• Construction is made out of light -conducting glass or plastic fibers at the center of a thick tube of protective cladding.

Two Basic Types of Fiber Optic Cable

• Multi-mode fiber optic cable refracts light toward the center of the fiber by variations on the density of the core.
• Single-mode fiber optic cable is the fastest fiber optic cable, where the light is guided down the center of an extremely narrow core.

Fiber Optic Cable Advantages and Disadvantages

• Advantages: Very low error rates, faster transmission rates, immune to environmental interference, high attenuation, and secured
• Disadvantages: costly for short distances, complex to configure and install, needs training/education and inability to add nodes.

Transmission Methods in Networking (Broadband Transmission)

• Signals are send at very high frequency to transmit over multiple channels. Fiber cables, cable television and DSL use them a lot.

Transmission Methods in Networking (Baseband Transmission)

• An entire bandwidth channels sends to one single signal. Ethernet networks uses this.

Broadband vs Baseband Transmission

• Broadband uses high-frequency carrier waves but baseband does not.
• Broadband supports multiple channels on a single cable while baseband transmission supports only one channel at a time.
• Cost is more for broadband because equipment is complex though baseband equipment is simpler and therefore less expensive.
• Broadband is used in cable TV, DSL and fiber optics while baseband is used within LAN Ethernet.
• For bandwidth utilization, broadband divides bandwidth into multiple channels but baseband users entire bandwidth.

Basic Concept of IPv4

• The fourth version of the Internet Protocol (IP) is used to identify devices on a network through an addressing system; it is responsible for routing packets across the internet.
• Operates on a best-effort delivery model.
• Does not guarantee the delivery of packets, their order, or protection against data loss or corruption.
• The data link Layer and Transport Layer allow for communication achieve reliability.

Explore network communication protocols, focusing on TCP/IP and data transfer. Understand data transmission accuracy, and the roles of ISO and IEEE. Learn how protocols ensure seamless device and system interoperability.