Networking Media
Overview CCNA 1 - Module 1 (3.1)
All matter is composed of atoms. The Periodic Table of Elements
Electrons stay in orbit
Electrons in certain atoms, such as metals, can be made to flow. Electricity = flow of electrons.
Static electricity and electrostatic discharge (ESD)
ESD can create serious problems for sensitive electronic equipment.
Atoms, or groups of atoms called molecules, can be referred to as materials.
Electromotive force (EMF)
Created by:
Semiconductors:
Closed loops
Considerations:
Variants:
Important to properly ground the cable!
CCNA has these two:
Wikipedia divides the first into two.
STP (in all variants) need to be grounded at both ends - otherwise noise.
Advantages
Disadvantages
Variants
Light - one type of electromagnetic energy
Radio, microwaves, radar, infrared, visible light, ultra violet, x-rays, and gamma rays.
300,000 kilometers per second = the speed of light.
Human eyes sense wavelengths between 700 nanometers and 400 nanometers (nm) = visible lightI
Infrared light:
"These wavelengths were selected because they travel through optical fiber better than other wavelengths."
Total internal reflection = All light is reflected back
The light will follow a zigzag path through the core of the fiber.
Optical paths through the core are called modes.
Two fibers in separate sheaths - full duplex. Single outer jacket until they reach the point at which connectors are attached.
Multimode fiber-optic cable is the most common fiber-optic cable in LANs.
Either a 62.5 or a 50- micron core and a 125-micron diameter cladding.
Light sources:
Advantages to multi mode
But it is more expensive!
Nine-micron cores are the most common: 9/125.
The infra red light is invisible, but it is strong enough to hurt the eyes! Never look into the end of a cable or into any other equipment.
LED
LASER
You may also see:
Splicing is hard. Carefully polish, inspect with a microscope!
"The connectors and the ends of the fibers must be kept spotlessly clean."
Optical loss meters and Optical time domain reflectometers
Networking Media
Overview CCNA 1 - Module 1 (3.1)
All matter is composed of atoms. The Periodic Table of Elements
Electrons stay in orbit
Electrons in certain atoms, such as metals, can be made to flow. Electricity = flow of electrons.
Static electricity and electrostatic discharge (ESD)
ESD can create serious problems for sensitive electronic equipment.
Atoms, or groups of atoms called molecules, can be referred to as materials.
Electromotive force (EMF)
Created by:
Semiconductors:
Closed loops
Considerations:
Variants:
Important to properly ground the cable!
CCNA has these two:
Wikipedia divides the first into two.
STP (in all variants) need to be grounded at both ends - otherwise noise.
Advantages
Disadvantages
Variants
Light - one type of electromagnetic energy
Radio, microwaves, radar, infrared, visible light, ultra violet, x-rays, and gamma rays.
300,000 kilometers per second = the speed of light.
Human eyes sense wavelengths between 700 nanometers and 400 nanometers (nm) = visible lightI
Infrared light:
"These wavelengths were selected because they travel through optical fiber better than other wavelengths."
Total internal reflection = All light is reflected back
The light will follow a zigzag path through the core of the fiber.
Optical paths through the core are called modes.
Two fibers in separate sheaths - full duplex. Single outer jacket until they reach the point at which connectors are attached.
Multimode fiber-optic cable is the most common fiber-optic cable in LANs.
Either a 62.5 or a 50- micron core and a 125-micron diameter cladding.
Light sources:
Advantages to multi mode
But it is more expensive!
Nine-micron cores are the most common: 9/125.
The infra red light is invisible, but it is strong enough to hurt the eyes! Never look into the end of a cable or into any other equipment.
LED
LASER
You may also see:
Splicing is hard. Carefully polish, inspect with a microscope!
"The connectors and the ends of the fibers must be kept spotlessly clean."
Optical loss meters and Optical time domain reflectometers