Welcome to CH1-Lesson 3! In this chapter, we’ll dive into the different types of transmission media, network topologies, and advanced network addressing concepts. These are essential for understanding the building blocks of modern networks and the technologies that support high-speed communication. Let’s get started!
1️⃣.5 Transmission Media and Transceivers 📡
Transmission media are the pathways that carry data between network devices. They can be wired or wireless, each with unique standards and characteristics.
Wireless Transmission Media
- 802.11 Standards: These define the protocols for Wi-Fi. They include:
- 802.11a: 5 GHz band, up to 54 Mbps.
- 802.11b/g: 2.4 GHz band, up to 11 Mbps and 54 Mbps, respectively.
- 802.11n: Operates on both 2.4 GHz and 5 GHz, up to 600 Mbps.
- 802.11ac: 5 GHz, supporting multi-gigabit speeds.
- 802.11ax (Wi-Fi 6): Advanced efficiency, higher capacity, and multi-gigabit speeds.
- Cellular: Uses 3G, 4G, 5G standards for mobile communication. It’s great for wide-area coverage but has latency concerns.
- Satellite: Provides global connectivity, even in remote areas. Often used for emergency communications.
Wired Transmission Media
- 802.3 Standards: Defines Ethernet technologies, including 10BASE-T to 100GBASE-T for speeds from 10 Mbps to 100 Gbps.
- Single-mode vs. Multimode Fiber:
- Single-mode Fiber: Supports long-distance communication due to a smaller core size.
- Multimode Fiber: Suitable for short distances and uses a larger core, but suffers from more signal loss.
- Direct Attach Copper (DAC) Cable: Short-distance, high-speed connections. Usually used for connecting servers in data centers.
- Twinaxial Cable: Similar to DAC but with enhanced shielding for signal integrity.
- Coaxial Cable: Used in traditional cable TV and older Ethernet connections. It’s highly resistant to interference.
Cable Speeds ⚡
- Cat5e: Up to 1 Gbps.
- Cat6/Cat6a: Up to 10 Gbps.
- Cat7/Cat8: Up to 40 Gbps and beyond for high-speed environments.
Plenum vs. Non-Plenum Cable
- Plenum Cable: Fire-resistant, used in ventilation spaces for enhanced safety.
- Non-Plenum Cable: Standard cables, not suitable for fire-prone areas.
Transceivers
Transceivers convert electrical signals to optical signals or vice versa, connecting various media types.
- Protocol:
- Ethernet: Common in LAN networks.
- Fibre Channel (FC): Often used in storage area networks (SANs).
- Form Factors:
- Small Form-Factor Pluggable (SFP): Commonly used in networking hardware.
- Quad Small Form-Factor Pluggable (QSFP): Higher capacity than SFP, typically used in high-speed applications.
- Connector Types:
- Subscriber Connector (SC), Local Connector (LC), Straight Tip (ST): Fiber connectors.
- Multi-fiber Push On (MPO): Used in multi-fiber connections.
- RJ11: Phone lines.
- RJ45: Ethernet connections.
- F-Type: Coaxial TV connections.
- Bayonet Neill–Concelman (BNC): Coaxial cable connectors for older networks.
1️⃣.6 Network Topologies, Architectures, and Types 🗺️
Understanding different network designs is crucial for deploying and troubleshooting networks. Let’s explore some common topologies and architectures.
Topologies
- Mesh: Every node connects to every other node. Offers redundancy but can be complex to set up.
- Hybrid: Combination of two or more topologies (e.g., mesh and star).
- Star/Hub and Spoke: Centralized model with one hub. Used in smaller networks.
- Spine and Leaf: Used in data centers to enhance scalability and speed.
- Point-to-Point: Direct connection between two nodes.
Three-Tier Hierarchical Model
- Core: High-speed backbone layer.
- Distribution: Connects core and access layers.
- Access: Directly connects to end devices.
Collapsed Core: Combines core and distribution layers for simpler networks.
Traffic Flows:
- North-South Traffic: Between the data center and external networks.
- East-West Traffic: Between servers within the same data center.
1️⃣.7 IPv4 Network Addressing 🧮
IPv4 addressing is foundational to configuring and maintaining networks.
Public vs. Private Addresses
- Public IP Addresses: Routable on the internet.
- Private IP Addresses: Used within internal networks (e.g., 192.168.x.x).
Automatic Private IP Addressing (APIPA): Used when DHCP fails. Format: 169.254.x.x.
RFC1918: Defines private IP address ranges (e.g., 10.x.x.x, 192.168.x.x).
Loopback/Localhost: Used to test networking stack on a local machine. Address: 127.0.0.1.
Subnetting: Dividing a network into smaller subnets for better traffic management.
Variable Length Subnet Mask (VLSM): Allows subnets of different sizes in the same network.
Classless Inter-Domain Routing (CIDR): An alternative to traditional IP classes, offering more flexibility (e.g., 192.168.0.0/24).
IPv4 Address Classes:
- Class A: Large networks (1.0.0.0 to 126.255.255.255).
- Class B: Medium-sized networks.
- Class C: Small networks.
- Class D: Reserved for multicasting.
- Class E: Reserved for experimental purposes.
1️⃣.8 Modern Network Environments 🖥️
Modern networking is rapidly evolving. Let’s look at some cutting-edge concepts:
Software-Defined Networking (SDN) and Software-Defined Wide Area Network (SD-WAN):
- Centralized control of network devices using software rather than manual configurations.
Zero-Touch Provisioning: Automates device configuration and deployment, reducing manual work.
Zero Trust Architecture (ZTA): Focuses on verifying every request as though it originates from an open network, ensuring least privilege access.
Secure Access Service Edge (SASE): Combines network security functions and WAN capabilities in a cloud-delivered service.
Infrastructure as Code (IaC): Uses code to define and manage network configurations, enabling automation and version control.
IPv6 Addressing: Solves IPv4 address exhaustion by using 128-bit addresses (e.g., 2001:0db8::/32).
- Tunneling: Encapsulating IPv6 packets within IPv4 for compatibility.
- Dual Stack: Running IPv4 and IPv6 simultaneously.
Now that we’ve covered CH1-Lesson 3 thoroughly, take some time to review these concepts. If you’re ready, why not test yourself on Kahoot or share your knowledge on Facebook and LinkedIn? 📈
CH1 Quiz : Kahoot
