Network Infrastructure Concepts Flashcards
Definition of a Network
Network: In its most simple form, a network consists of two or more computers connected to each other by an appropriate transmission medium that allows them to share data.
Give all types of networks
Types: LANs, WANs, MANs
What is the purpose of a network?
Purpose: Provide services and resources to users
What are the modern forms of networks?
Modern: web applications, social networking, VoIP, multimedia conferencing
What historically would share data over a network?
Historically: files, folders, printers, email, databases
What are LANs based upon
Ethernet (networking product)
Who developed Ethernet
DIX consortium( Digital Equipment Corporatio[DEC],Intel and Xerox)
Who maintains Ethernet standards
Maintained by IEEE [Institute of Electrical and Electronics Engineers] (802.3 standards)
Give all types of Ethernet
Types:
10 Mbps (10BASE)
Fast Ethernet (100BASE)
Gigabit Ethernet (1000BASE)
10G Ethernet (10GBASE)
True or False
Ethernet is not flexible, self-contained, scalable
False
Ethernet is flexible, self-contained, scalable
What is complementary to IEEE 802.11 standards (Wi-Fi)
WLANs
What are the two classes of LANs
SOHO and Enterprise Network
Definition of SOHO
SOHO: business network with server and clients, using single Internet appliance as an access point, Ethernet switch, Internet modem, Internet router.
Definition of Enterprise Network
Enterprise network: usually dedicated single-function connectivity appliances.
Definition of SME
Small and Medium-Sized Enterprise (SME): network supporting tens of users; multiple switches, access points, routers.
Definition of Enterprise LAN
Enterprise LAN: hundreds or thousands of servers and clients; multiple enterprise-class switches, access points, and routers.
Definition of CAN
Campus Area Network (CAN) = LAN spanning multiple nearby buildings.
Definition of UTP
UTP: Unshielded Twisted Pair
Features of UTP
Most widely used
Four copper conductor pairs
Insulating sheath
Twisted to reduce crosstalk and EMI
Paired wires carry equal/opposite signals
PVC jacket
Works well in low interference; has limited range, may exhibit attenuation
What are the standards for CAT 5
Frequency: 100 MHz
Capacity: 100 Mbps
Max Distance : 100m (328 ft)
Network Applications: 100BASE-TX
What are the standards for CAT 5e
Frequency: 100 MHz
Capacity: 1 Gbps
Max Distance : 100m (328 ft)
Network Applications: 1000BASE-T
What are the standards for CAT 6
Frequency: 250 Mhz
Capacity: 1 Gbps or 10 Gbps
Max Distance : 100m(328 ft) or 55m(180 ft)
Network Applications: 1000BASE-T or 10G BASE-T
What are the standards for CAT 6A
Frequency: 500 Mhz
Capacity: 10 Gbps
Max Distance : 100m(328 ft)
Network Applications: 10GBASE-T
Definition of STP
STP: Shielded Twisted Pair
Features of STP
Shielded Twisted Pair (STP)
Originally used the braided shield to reduce interference and crosstalk; can be bulky, difficult to install.
Modern STP uses screened cables; shield positioned around all pairs.
Shielded Cat 53/6/6A:
F/UTP (also ScTP)
U/FTP
Modern STP solutions incorporate grounding in each element.
Definition of Plenum
Plenum: An air handling space, including ducts and other parts of the HVAC system in a building.
Features of Plenum Space
Typically a false ceiling, maybe raised floor.
May be used for communications wiring.
Can be the conduit for fire.
What does general-purpose(non-plenum) use
General-purpose non-plenum cable uses PVC; marked CMG/MMG or CM/MP
True or False
Plenum cable must not emit smoke, must self-extinguish, meet other fire safety standards.
True
Features of Plenum
Uses treated PVC or FEP; can be less flexible, does not affect bandwidth.
Marked CMP/MMP.
For what modular does twisted pair cabling for Ethernet terminated
RJ-45 connectors
Features of Ethernet twisted pair terminated with RJ-45 connectors
8P8C (8-position/8-contact)
Color-coded (Blue, Orange, Green, Brown)
1st conductor in pair has white/stripes
2nd conductor in pair is a solid color
Features of ANSI/TIA/EIA 568 termination
T568A is shown
T568B:
Pin 1=Orange/White; Pin 2=Orange; Pin 3=Green/White; Pin 4=Green
What cable has the same termination at both ends?
Normal (straight-through) cable
Wiring Standards for Twisted Pair:
Features of crossover cable that has T568A at one end, T568B at the other.
Previously used for direct connections.
Now Gigabit Ethernet interfaces can automatically cross over with standard cable.
Wiring Standards for Twisted Pair:
Why should you avoid mixing standards
Both are common.
T568A mandated for US government and by TIA 570 residential cabling standard
True or False
Gigabit Ethernet has no more than 100 m of cable between switch and computer
True
Features of solid cabling
Single thick wire for permanent links, aka “drop cables”
Links RJ-45 port on a wall plate with patch panel
Terminates in IDC
Features of patch cord connects RJ-45 port on the panel to port on the switch
Stranded cable; flexible, less efficient
5 m maximum length
Definition of wire stripper/cutter
Wire stripper/cutter: for cutting wire and stripping insulation and cable jackets.
Definition of punch-down tool
Punch-down tool: fixes conductors into an IDC.
Definition of crimper
Crimpers: fix a jack into a cable.
What should you do when you cable test.
Cable testing:
Verify wiring installation and termination just after making connections, with access to cable runs.
Simpler than during user device setup.
Consider:
Patch cord between PC and wall.
Wall port and wall cabling.
The port on the patch panel and a patch cord to the switch port.
Test with a known good cable.
Various troubleshooting devices.
Definition of Multumeter
Multimeter: basic cable testing tool; tests for copper wire continuity, the existence of short, the integrity of terminator.
Definition of Wire Map Tester
Wire map tester: identifies transpositions and reverse pairs.
Definition of Advance Testers
Advanced testers: show cable’s physical/electrical properties.
Definition of Certifiers
Certifiers: test and certify installation to a category.
Definition of Loopback plug
Tests a port
Connects pin 1 to pin 3 and pin 2 to pin 6
What are electrical signals on copper wire subjects too?
To interference/attenuation.
What does light signals on fiber optic cable resist
Interference, eavesdropping, attenuation.
What does fiber optic cables support
Supports higher bandwidth, longer cable runs.
What is SMF
Single-Mode Fiber
What is MMF
Multi-Mode Fiber
Features of SMF
Small core, long-wavelength, near-infrared signal generated by the laser.
Data rates up to 10 Gbps or more; cable runs of many kilometers (suitable for WANs).
Features of MMF
Larger core, shorter wavelength.
Less expensive optics, less expensive deployment.
Lower signaling speeds, shorter distances (suitable for LANs).
What are the types of connectors for fiber optic cabling
Straight Tip (ST), Subscriber Connector (SC), Lucent/Local Connector (LC).
True or False
Patch cords can have the same or mixed connectors.
True
True or False
Connectors damage easily; plug/unplug only when needed.
True
Features of Coaxial Cabling
Two conductors share the same axis.
Signal conductor insulated; second wire mesh conductor acts as EMI shield and as ground.
What is coaxial cabling available as
Coax is also available with tri- or quad-shielding.
What is RG(Radio Graded) standard categorize by
categorizes cable by thickness and impedance.
Types of Coaxial Cabling by the RG standard
RG-6: thicker core, better quality, often used as drop/patch cable in modern CATV and broadband.
RG-59: thinner core; drop cable for older CATV/cable modems; used in CCTV.
What is coaxial cabling shielding is also available?
Coax is also available with tri- or quad-shielding.
What connectors are at the ends of coaxial cabling?
BNC connectors at cable end in most cases.
Also screw-down F-connectors.
What connects coaxial cables
BNC couplers can connect cables.
What cable types must the impedance of the coaxial cable match.
50 or 75 ohm
What do 10BASE-5/Thicknet and 10BASE-2/Thinnet support
Supported 10 Mbps, up to 500 m and 185 m, respectively.
Coax is now obsolete for LANs but what is it used for.
In use for CCTV and drop cables for CATV and Internet.
What does a Hybrid Fiber Coax (HFC) do?
Coax links fiber trunk in street to a customer cable modem.
Less attenuation than TP but bulkier, harder to install.
Definition of NIC
Network Interface Card (NIC) port provides a connection to network media.
Features of NIC
Data signals must come in regular units with a consistent format.
Each node must be able to address other nodes.
Ethernet data link protocol provides addressing, framing functions.
Various encoding mechanisms; NIC transceiver transmits and sends in agreed frame format.
Where is the NIC in a PC
Usually onboard the motherboard.
Features of NIC
Maybe PCIe expansion board.
All onboard cards support copper-based Ethernet with RJ-45 ports.
Expansion cards may support:
Fiber optic.
Multiple port types.
Multiple ports of the same type (can be bonded for higher-speed links).
Defintion of a MAC adresss
MAC address: unique address for each Ethernet adapter port.
What does a MAC address provide
Provides value for frame source and destination fields.
How many bytes does a MAC address contain
48 bits/6 bytes.
How is a MAC address shown
Shown as 12 hex digits:
May have colon, hyphen, or no separator.
Examples: 00:60:8c:12:3a:bc or 00608c123abc.
What does a LED status show?
Show connection status
Features of a LED that’s part of an Ethernet NIC
Link light shows if the network signal is present.
Activity light flickers when packets are received/sent.
Speed light possible on multi-speed adapters.
Dual-color LEDs combine functions.
Give all legacy networking appliances and definitions
Legacy appliances include:
Hub: center of Ethernet star topology, works as a multiport repeater.
Repeater: retransmits the signal to overcome distance limitations.
Bridge: divides the network into segments (collision domains) to reduce contention and collision.
True or False
A switch is not an appliance at the core of modern networks.
False
A switch is an appliance at the core of modern networks.
In a modern network what does act like.
Ethernet switch in the modern network acts like a hub, repeater, and bridge.
Features of micro-segmentation
Switches have up to 48 ports.
Multiple switches can connect to the switched fabric with thousands of ports.
Each port is a separate collision domain.
Establishes point-to-point link (virtual circuit) between any two nodes.
Collisions only occur if the port is half-duplex (attached to a legacy card or node).
Collisions only affect that segment, not the whole network.
Features of an unmanaged switch
Unmanaged switch:
Performs micro-segmentation without configuration.
May be found in small networks (4 or 8 port switches).
Embedded in most ISP’s Internet routers/modems.
Features of a managed switch
Managed switch:
For larger workgroups and corporate networks.
Unmanaged out of the box, but can be configured administratively.
Can provide thousands of access ports by linking switches.
Can divide into virtual LANs (VLANs).
Definition of Power over Internet
Supplies power from a switch port over Cat 5 or better to a powered device.
Features of PoE
PoE-enabled switches are called end-span/end-point PSE.
A power injector can be used if the switch does not support PoE.
The switch detects if the connected device is PoE-enabled.
More efficient than powering each device through a wall socket.
Network-management software can control devices, apply power schemes.
Give all the two standards for PoE
Two IEEE standards (both now in 802.3-2012):
802.3af
802.3at (PoE+)
Features of Ethernet of Power
SOHO networks are unstructured, use a single router, incorporate smart appliances.
Wireless is an obvious solution; WLAN bandwidth may be adequate.
There may be interference issues or appliances may not support Wi-Fi.
Ethernet over Powerline uses building power circuits; overlays carrier signal to transfer Ethernet frames.
The adapter plugs into an electrical outlet; provides RJ-45 ports.
No configuration is needed, but security can be configured.
Standards defined by IEEE 1901, managed by HomePlug Powerline Alliance.
What is Wireless Networking?
A range of connectivity products and devices.
Personal area networking to Internet connectivity.
Usually uses radio waves for transmission, tuned to a specific frequency.
What is the range of RF
RF ranges from 3 KHz to 300 GHz
Give all features of wireless frequencies and channels
Subdivided into bands (FM radio and TV are VHF band)
Radio spectrum use regulated by governments
Standardized by ITU
Frequency use requires a license
Some unregulated frequencies
What standard does Wifi equal?
IEEE 802.11 standards = Wi-Fi
(Transfer rates for optimal installation; frequencies lack penetration; may be interference; data rate may drop with distance.)