Network Types and Connections

• Computer networks facilitates data exchange and communications between interconnected devices
• Networks enhance productivity, improve access to information, and support services like internet connectivity/file sharing/remote access

Types of Networks

• Local Area Networks (LANs) connect computers in a limited area like a home, school, or office for high-speed data transfer and resource sharing
• Wide Area Networks (WANs) cover large geographic areas and connect multiple LANs, often using leased telecommunication lines. The Internet serves as an example of WANs
• Metropolitan Area Networks (MANs) span a city or campus and are commonly used by universities and businesses to connect locations within urban areas
• Personal Area Networks (PANs) connect personal devices within a few meters, such as smartphones/tablets/laptops via Bluetooth

Network Topologies: Advantages

• Star topology provides easy management and troubleshooting because of its centralized structure
• Mesh topology offers high redundancy and reliability due to multiple data transmission paths
• Bus topology is cost-effective, needing less cabling than other topologies
• Ring topology enables predictable data transmission as data travels in one direction

Network Topologies: Disadvantages

• Star topology requires more cabling, and implementation can be costly
• Mesh topology can be overly complex and expensive, especially in large networks due to the number of connections
• Bus topology can lead to performance issues as more devices are added, and a failure in the main cable can bring down the entire network
• Ring topology can suffer from latency issues, and failure of a single device can disrupt the entire network

Key Network Devices

• Routers connect networks, directing data packets, support complex routing protocols, and include firewall and security features
• Switches connect devices within the same network, using MAC addresses to forward data at the Layer 2
• Hubs connect Ethernet devices, function as a single network segment, and broadcast data to all ports, which reduces efficiency

OSI Model Explained

• Physical Layer (Layer 1) transmits raw bitstreams over a physical medium and deals with cables and connectors
• Data Link Layer (Layer 2) provides node-to-node data transfer and error detection/correction and ensures reliable communication between devices in a local network
• Network Layer (Layer 3) is responsible for data routing, packet forwarding, and addressing and determines the optimal path for data transmission across networks
• Transport Layer (Layer 4) ensures complete data transfer, controls data flow, offers error recovery plus flow control and can segment data for transmission
• Session Layer (Layer 5) manages sessions between applications through establishing/maintaining/terminating connections and ensures synchronization
• Presentation Layer (Layer 6) translates data formats, encrypts/decrypts data, and ensures data is in a readable format

TCP/IP Model

• The TCP/IP model consists of four layers: Application/Transport/Internet/Network Access
• The U.S. Department of Defense developed it to standardize networking protocols
• Each layer has functions; Application handles end-user services, Transport manages data transfer, Internet routes data, and Network Access interfaces with the network

Comparison with the OSI Model

• The OSI model has seven layers, while the TCP/IP model has four, that grouping similar functions together
• The TCP/IP Application layer is equivalent to the OSI Application/Presentation/Session layers
• The TCP/IP Transport layer is similar to the OSI Transport layer since it focuses on reliable end-to-end communication

Comparing OSI and TCP/IP Models

• The OSI model has seven layers, while the TCP/IP model has four layers by combining certain functions
• Used/Developed: the OSI model was developed as a theoretical framework, while the TCP/IP model was created based on practical implementation for the internet
• Protocol Support: the TCP/IP model is associated with particular protocols (TCP, IP), while the OSI model serves as a guide for protocols across its layers
• Flexibility/Usage: TCP/IP is used in real-world applications including internet, and OSI is primarily used for teaching networking concepts

Networking Media Types

• Wired media includes Ethernet/fiber optic cables and provides high-speed/reliable connections for Local Area Networks (LANs)
• Wireless media uses Wi-Fi and Bluetooth, connecting devices without physical cables and is suitable for mobile/flexible networking
• Wired media generally offers faster speeds and lower latency compared to wireless media, but wireless media provides convenience and mobility

Cabling Types

• Crossover cables connect similar devices switch to switch/computer to computer so data can transfer directly without a hub or switch
• Straight-through cables are the most common type of network cable and are used to connect devices like computers to switches or routers to ensure communication
• Rollover cables connect to routers and switches to access the device's command-line interface in order to configure them

Network Components Identification

• Routers connect multiple networks, directing data packets based on IP addresses
• Switches connect devices in a single network, using MAC addresses to forward data
• Cables and Connectors: Ethernet/fiber optic cables connect network components, using connectors like RJ45

Packet Tracer

• Packet Tracer allows users to create/visualize network topologies without physical hardware and practice configuring those in real-world scenarios
• Has dragging and dropping, plus configuring and simulating

Basic Network Topology Simulation

• Open Packet Tracer and familiarize interface
• Drag and drop routers, switches, and PCs from the device toolbar onto the workspace in desired topology design.
• Then Link devices with the connection tool with appropriate cable
• Connect devices using appropriate cabling
• Assign IP addresses to each subnet to enable communication and troubleshoot issues after by testing connectivity

Ethernet Cable Types

• Cat5e (Enhanced Category 5) cables support speeds up to 1 Gbps and are used for standard home/small business networking
• Cat6 cables handle speeds of up to 10 Gbps over short distances and they are used for high-speed data transfer
• Cat7 cables support speeds up to 10 Gbps and offer shielding for less signal interference

Hands on Identifying Cables

• Gather networking cables like Crossover/Straight-Through/Rollover
• Inspect each cable and identify: pin configuration, color coding, and intended use
• Verifying Cables: use a cable tester
• Accurately Identify: document findings and compare them with classmates

Creating Network Topologies

• Understand organizational specific needs, like number of devices, data traffic, and scalability
• Select appropriate topology (star, ring, bus, or mesh) based on identified needs, along with cost plus performance
• Design for future growth by allowing devices to be added in with ease
• Incorporate redundancy to ensure continuous operation in case of a failure
• Assess all costs to determine, equipment, installation, and maintenance required

Network Design Best Practices

• Design for future growth in mind, easy integration of additional devices and higher bandwidth
• Use redundant paths and devices to ensure network reliability plus minimize downtime
• Utilize a hierarchical network design model to improve organization, management, and performance
• Select appropriate technologies with hardware that match the network's performance
• Maintain detailed documentation of architecture, software, configurations, and future upgrades.
• Monitor network performance, security update, and hardware, plus improve efficiency

Cabling Best Practices

• Label Cables: Use consistent labels to simplify identification and troubleshooting
• Use trays/ties/racks to organize/reduce clutter
• Keep cables sources of electromagnetic interference
• Adhere to TIA/EIA standards for compatibility/performance
• Conduct routine checks on cabling for where and tear

Common Networking Issues

• Network connectivity problems: may arise from incorrect configurations, hardware failures, or cable faults
• Slow Network Performance can be caused by bandwidth limitations, network congestion, or faulty hardware
• IP Address Conflicts: Occurs if two devices use the same IP address, fix by proper DHCP configurations
• Wireless interference: Caused by Obstacles and electronic devices due to Wi-Fi signals, can fix by repositioning routers plus changing channels

Explore different network types: MANs for city-wide connectivity, LANs for local connections, and PANs for personal device connections. Understand WANs that span large areas and the benefits of centralized network management. Also, learn about crossover and straight-through cables for device connections.