CCNA Completo | Leccion 4 | Capa física | Fibra óptica
Introduction to Fiber Optic Transmission
Overview of Fiber Optic Technology
- The tutorial introduces the topic of fiber optic transmission as part of a comprehensive CCNA course, emphasizing its advantages over other transmission media.
- Fiber optic cables transmit data over longer distances and with higher bandwidth than copper cables, while also being immune to electromagnetic interference.
Components of Fiber Optic Cables
- A fiber optic cable consists of a core (nucleus), which is the physical medium that carries optical signals. The core is made from glass or plastic and measured in microns.
- Common core sizes for multimode fibers are 50 micrometers and 62.5 micrometers, while single-mode fibers typically have cores less than 9 micrometers in diameter.
Types of Multimode Fiber
Step Index vs. Graded Index
- Multimode fiber allows multiple light rays to travel through the core via different paths; it includes two types: Step Index and Graded Index.
- In Step Index fibers, the density remains constant from center to edge, causing abrupt changes in light path at the boundary between core and cladding, potentially distorting signals.
- Graded Index fibers have a varying density that decreases towards the edges, reducing signal distortion during transmission.
Categories of Multimode Fibers
- TIA/EIA recognizes four categories of traditional multimode fibers; older categories like OM1 and OM2 are no longer suitable for high-speed applications.
- Modern options include OM3 and OM4 fibers designed for laser light sources, identifiable by their aqua or light blue outer jackets.
Single Mode Fibers
Characteristics and Applications
- Single mode fibers feature smaller core diameters compared to multimode fibers; they require highly focused light sources and are used primarily for long-distance applications such as internet service providers.
Connectors and Patch Cords
Types of Connectors
- Various connectors exist for fiber optics; notable ones include ST connectors (early designs), SC connectors (widely adopted in LAN/WAN installations), and LC connectors (smaller version gaining popularity).
Usage Considerations
- Patch cords connect intermediate devices; color coding helps distinguish between single mode (yellow covers) and multimode patch cords (orange/aqua covers).
Switches with Optical Ports
Requirements for Ethernet Switches
- To use fiber optics with Ethernet switches, one needs switches equipped with specific optical ports or modular ports allowing selection based on requirements.
Example Equipment
- An example shown includes a switch with four SFP Plus modular ports capable of supporting various standards up to 10 Gigabits per second.