Media and Cabling Distribution (1.3 & 5.2) Flashcards
Media
o Material used to transmit data over the network
Copper Media
o Types of Media
▪ Three categories:
● Copper
● Fiber optic
● Wireless
▪ Each category is divided into subcategories
▪ Each has different specifications and uses
Coaxial Cable (Coax) (insulated conductor to help pass data / protected shield for data transmission / EMI resistance)
▪ Inner
● Insulated conductor or center wire passes data
▪ Outer
● Braided metal shield used to help shield and protect the data transmission
● Provides EMI resistance due to shielding
Coaxial Cables (RG-6 = thicker use for cable companies outside / RG-59 = thiner, used for nearby devices, cable box to TV
▪ RG-6
● Commonly used by local cable companies to connect individual homes
▪ RG-59
● Typically used to carry composite video between two nearby devices, such as from a cable box to the television
Coaxial Connectors (F-Connector = TV and cable modem / BNC = 10BASE2 ethernet)
▪ F-connector
● Typically used for cable TV and cable modem connections
▪ BNC
● Termed Bayonet Neill-Concelman or British Naval Connector
● Was used for 10BASE2 Ethernet networks
Twinaxial Cable (two innerconductors instead of one to carry data)
▪ Similar to coaxial cable but uses two inner conductors to carry the data instead of just one
Serial Cable (9 pin or 25 pin D-subminiature / asynchronous communication and connecting to external modem)
▪ Usually have a series of straight copper wires inside a single cable or plastic jacket
▪ DB-9 or DB-25 (RS-232)
● 9-pin or 25-pin D-subminiature
● Used for asynchronous serial communications and connecting to an external modem
Twisted Pair Cables
▪ Most popular physical LAN media type
▪ Eight individually insulated strands of copper wire inside each cable
▪ Each pair twisted together to reduce EMI
● Tighter twists = less EMI
▪ Types:
● Unshielded Twisted Pair (UTP)
● Shielded Twisted Pair (STP)
Unshielded Twisted Pair (UTP) (more twists = more EMI / cheaper / choice in most LAN’s)
▪ Number of twists determines how much EMI can be blocked
● CAT 6 has more twists per inch than CAT 5
▪ UTP is cheaper than STP
▪ Media of choice in most LANs
Shielded Twisted Pair (STP) (metallic shielding, thus minimizing EMI / costs more than UTP)
▪ Wires are twisted in pairs and surrounded in a metallic shielding to minimize EMI
▪ Outer shielding minimizes EMI, but makes STP cost more than UTP
Twisted Pair Connectors
▪ RJ-45
● 8-pin connector in Ethernet networks
● Most Ethernet use only 4-pins
▪ RJ-11
● 6-pin connector
● Commonly only 2 or 4 pins are used
● Commonly found in telephone systems
Registered Jack (RJ)
▪ Used to carry voice or data which specifies the standards a device needs to meet to connect to the phone or data network
Bandwidth
▪ Theoretical measure of how much data could be transferred from a source to its destination
Throughput
Actual measure of how much data transferred from a source to its destination
Cable Lengths
▪ Keep cable runs under 70 meters from the IDF to the office
Straight-Through Patch Cables
▪ Contains the exact same pinout on both ends of the cable
▪ T-568B is the preferred standard for wiring a building if no pre-existing pattern is used
● Data Terminating Equipment (DTE)
o “Endpoint” devices that connect to a piece of data communications equipment or DCE (e.g. laptops, desktops, servers, and routers)
● Data Communications Equipment (DCE)
o Includes things like switches, modems, hubs, and bridges
● Connecting DTE and DCE devices
o Straight-through
▪ DTE to DCE
▪ DCE to DTE
o Crossover
▪ DTE to DTE
▪ DCE to DCE
Crossover Cables
▪ Swaps the send and receive pins on the other end of the cable when the connector and its pinout are created
Pinouts (568A/568B)
▪ TIA/EIA-568A and TIA/EIA-568B are standard
▪ Orange and Green pairs swap
Medium Dependent Interface Crossover (MDIX)
▪ An automated way to electronically simulate a crossover cable connector even if using a straight-through patch cable
▪ If a switch doesn’t support MDIX, use a crossover cable to make them talk
Plenum and Non-Plenum Cable
▪ Plenum Cable
o A special coating put on a UTP or an STP cable that provides a fire-retardant chemical layer to the outer insulating jacket
o Minimizes dangerous fumes if cable on fire
o Safe for use in ceilings, walls, and raised floors
▪ Non-plenum Cable
● Also known as PVC
● Normal UTP/STP rated cable
● Cannot be used in raised floors, ceilings, or walls
Types of Fiber Media
Fiber Optic Cables
▪ Uses light from an LED or laser to transmit information through a glass fiber
● Immune to EMI
● Uses light instead of electricity
▪ Benefits:
● Greater range (many miles)
● Greater data-carrying capacity (measured in Tbps)
▪ Types:
● Multimode Fiber (MMF)
● Single-mode Fiber (SMF)
Single-Mode Fiber (SMF)
▪ Used for longer distances and has smaller core size which allows for only a single mode of travel for the light signal
▪ SMF’s core size is 8.3-10μ in diameter
Multimode Fiber (MMF)
▪ Used for shorter distances and has larger core size which allows for multiple modes of travel for the light signal
▪ MMF’s core size is 50-100μ in diameter
▪ Up to 2 kms or less
Wavelength Division Multiplexing (WDM)
▪ Combines multiple signals into one signal and sends over a single fiber optic strand using different wavelengths of the laser light source
Types of Transceivers
Copper vs Fiber Optic Cables
▪ Fiber-Optic Advantages
● Higher bandwidth
● Longer distances
● Immune to EMI
● Better security
▪ Copper Advantages
● Less expensive
● Easy to install
● Inexpensive tools
Media Converters
▪ Convert media from one format to another
▪ Layer 1 device
● Physical conversion of signal only
▪ Examples:
● Ethernet to Fiber Optic
● Fiber Optic to Ethernet
● Coaxial to Fiber
● Fiber to Coaxial
Transceivers
▪ Device that sends (transmits) and receives data
● Bidirectional
o Devices take turns communicating
o Known as half-duplex
● Duplex
o Full duplex occurs when devices can both communicate at the same time
o Half duplex occurs when devices can either transmit or receive, but cannot do both at the same time
● Types of transceivers used in switches and routers
GBIC
▪ Standard, hot-pluggable gigabit Ethernet transceiver (copper or fiber)
Small Form-factor Pluggable (SFP)
▪ Compact, hot-pluggable optical module transceiver
▪ Support up to 4.25 Gbps
▪ Known as Mini-GBIC
SFP+
▪ Enhanced SFP
▪ Support up to 16 Gbps
Quad Small Form-factor Pluggable (QSFP)
▪ Compact, hot-pluggable optical module transceiver ▪ Supports up to 100 Gbps
Cable Distribution
o An organized system to connect the network’s backbone in the main distribution frame to the intermediate distribution frames and finally to the end user’s wall jacks
Cable Distribution System
▪ Use an organized system that is hierarchical
● Demarcation point
o The entrance facilities where you WAN connection will enter your building
▪ Components
● Entrance facilities
● MDF
● Cross-connect facilities
● IDF
● Backbone wiring
● Telecommunications closet
● Horizontal wiring
● Patch Panels
● Work area
Punch Down Blocks
▪ 66 block
● Used for phones and older LAN wiring
● Causes crosstalk due to proximity of cables
● Bad choice for higher-speed LAN wiring
o Do not use for CAT 5 or above
▪ 110 block
● Used for higher-speed network wiring
o Required for CAT 5 or above cabling
▪ Krone block
● A proprietary European alternative to a 110 block
▪ BIX block
● Another proprietary punch down block that comes in various sizes
● If you are going to work on a BIX block, you will need a BIX-specific punch down tool
Patch Panels (Copper)
▪ Device with jacks to connect wiring from the jack to a network switch in a flexible manner
▪ Has punch downs (like a 110 block) on the back side that is used to connect wiring to wall jacks in building
▪ Front has RJ-45 jacks
Patch Panels (Fiber)
▪ Connect fiber jacks throughout building to a single patch panel in network closet
▪ Front uses patch cables to connect different wall jacks and switch ports
Example of Cable Distribution
