An Introduction to Networking Chapter 1
Jan 21, 2016
An Introduction to Networking
Chapter 1
You will:
• List the advantages of networked computing relative to standalone.
• Distinguish between client/server and peer-to-peer networks.
• List elements common to all client/server networks.
• Describe several specific uses for a network.
• Identify some of the certifications available.
• Identify the kinds of skills and specialization that will help.
Topics
Networking Terminology
Network Topologies
Network Building Blocks
Standard Network Models
Network Categories
Two basic types of Networks
• LAN
A WAN
– A network that spans multiple geographic locations.
Network Definitions
• ServerServer:– A networked device that shares its resources with other
devices.
• ClientClient:– A personal computer or workstation in that requests
services from a server
• PeerPeer:– A self-sufficient computer that acts as both a server and a
client
• Host:Host:– Main frame type device that does all the processing
• Terminal:Terminal:– Usually dumb consists of a keyboard and a low-grade
video display and does not do processing.
Networks
• Definition:– A group of computers that are
connected together to communicate and share resources such as files, printers, and email.
S
Servers
General purposeGeneral purpose DedicatedDedicated
Server Server
• Definition:– A network computer that shares
resources with and responds to requests from other network computers, including other servers.
Types of Servers
• File Server• Print Server• Proxy Server• Application Server• Web Server• Mail Server• Fax Server• Remote Access Server• Telephony Server
Host Computers
• Definition:– A powerful, centralized computer system,
such as a mainframe computer, that performs data storage and processing tasks on behalf
of clients and other network devices.
Processing and storageProcessing and storage
Network devices
Host Computers
• The term host can also refer to a workstation and server and is most commonly used when discussing TCP/IP-related services and functions.
• A host, in TCP/IP terms, is any network device that has an IP address. – Workstations,– servers, and – any other network device (as long
as it has one or more IP addresses).
Peer-to-Peer Network
• Definition:– A self-sufficient computer that acts as
both a server and a client to other similar computers on the network.
Peer
Client and serverClient and server
Client and serverClient and serverClient and serverClient and server
Peer-to-Peer Network
Resources
Processing
Communication
Resources
Processing
Communication
Resources
Processing
Communication
Client/Server Network
• Definition:– A network computer that utilizes the
resources of other network computers
including other clients.Client 2Client 1
Processor, memory, storage
Processor, memory, storage
Terminals
• Definition:– A specialized network device on a host-
based network that transmits the data entered by the user to the host for processing and displays the results.
Terminal
No processorand no memoryNo processor
and no memory
Client
Authentication
• Definition:– A network security measure in which a
computer user or some other network component proves its identity in order to gain access to network resources.
Who I amWho I am
How do I know?How do I know?
User name & passwordUser name & password
ApprovedApproved
Encryption
• Definition:– A network security measure in which
information is encoded or scrambled prior to transmission so that it cannot be read unless the recipient knows the decoding mechanism, or key.
Ox12jOx12j DataData
Encrypted data
Client Server
Decrypted data
Network Directories
• Definition:– A centralized database that includes
objects such as servers, clients, computers, user names, and passwords.
Centralizedadministration
Centralizedadministration
AuthenticationAuthentication
Network Topologies
• Physical Topology– Bus– Star– Ring– Mesh
• Logical Topology
A Physical Bus Topology
Terminator TerminatorT-connector T-connectorT-connector
A Physical Star Topology
Hub
Node
A Physical Ring Topology
A Physical Mesh Topology
A Hybrid Topology
A Logical Bus Topology
Sender Receiver
ReceiverReceiver
A Logical Ring Topology
A Logical Star Topology
Polls nodes and controls accessPolls nodes and controls access
Network Topologies
• Includes:– Nodes– Backbone– Segments– Subnets
Nodes
• Definition:– Any network device that can connect to
the network and can generate, process, or transfer network data.
Backbones and Segments
• A Backbone is the part of the network to which all segments and servers connect.
Backbones
• Definition:– The highest-speed transmission path
that carries the majority of the network data. Backbone
Segments
• Any discrete physical subdivision of a network.
SegmentSegment
Subnets
• A portion of a network that shares a common network address.
VLAN
Standard Network Models
• Centralized Computing Network
• Client/Server Network• Peer-to-Peer Network• Mixed Mode Networks
Centralized Computing Network
CommunicationCommunication
ProcessingProcessing
StorageStorage
Host
UserUser
Client/Server Network
Processing powerProcessing power
Management servicesManagement services
Administrative functionsAdministrative functionsServer
Client 2Client 1
Mixed Mode Networks
Host
Server Peer/Client
Peer/Client
Network Topologies
PhysicalPhysical
LogicalLogical
The Internet
An Intranet
Employee handbook
An Extranet
Company A
Company B
Company C
An Enterprise Network
InternetWANLAN
Network technologies LANWAN
Organization
Network Media and Hardware
• Bounded Network Media• Unbounded Network Media• Noise Control• Network Connectivity Devices
Terms to Know
• Signals:– Electromagnetic communications
you want to be transmitted across a network medium
• Noise:– Electromagnetic interference that
disrupts the signal.• Attenuation:
– Degradation of a signal as it travels across a network medium, usually caused by the accumulation of noise or fading strength of the signal.
Media Types
Bounded mediaBounded media
Unbounded mediaUnbounded media
Physical Media
• Three types of cable– Coaxial Cable– Twisted-Pair Cable– Fiber-Optic Cable
Coaxial Cable
Braided shieldingBraided shielding
Single copper conductor
Single copper conductor
Non-conductiveinsulated coating Non-conductive
insulated coating
• Male BNC
• Barrel
• T-Connector
• Terminator
Uses BNC connectors
F-Type Connectors
• The F-Type connector is a threaded, screw-on connector that differs from the BNC connector of early Ethernet mainly in its method of device attachment.
Twisted Pair Cable
Conductors are stripedConductors are striped
Pair has basecolor schemePair has basecolor scheme
Primary and secondary wirePrimary and secondary wire
UTP vs. STP Cable
Cable Type Description
UTP
Does not include shielding around its conductors. Typically contains four pairs of stranded or solid conductors. Inexpensive and reliable. Supports distances of up to 100 meters (328 feet). Supports data transfer rates up to 1 Gbps.
STP
Includes shielding, typically a foil wrapper, around its conductors to improve the cable's resistance to interference and noise. Typically contains four pairs of stranded or solid conductors. Supports distances up to 100 meters (328 feet). More expensive than UTP. Most commonly used in Token Ring networking.
Twisted Pair Cable Categories
Category Network Type Maximum Speed
1Voice grade; not suitable for networking
n/a
2Digital telephone and low speed networks
4 Mbps
3 Ethernet 10 Mbps
4 IBM Token Ring 16 Mbps
55e
Fast EthernetGigabit Ethernet
100 Mbps350 Mbps
6 Gigabit Ethernet 1 Gbps
7 Gigabit Ethernet 1 Gbps+
An RJ-45 Connector
1 W/Green2 Green3 W/Orange4 Blue5 W/Blue6 Orange7 W/Brown8 Brown
P3
P1 P2
P4
Pin and Wire Colors
RJ-45 with locking tab facing away
Pin 1 Pin 8
Connector Pin - Out
EIA/TIA COLOR SCHEME 568 A 568B
1- Tx (+) 1- WHT/Green 1-WHT/Orange
2- Tx (-) 2- Green 2- Orange
3- Rx (+) 3- WTH/Orange 3- WHT/Green
4- 4- Blue 4- Blue
5- 5- WHT/Blue 5- WHT/Blue
6- Rx (-) 6- Orange
6- Green
7- 7- WHT/ Brown 7- WHT/Brown
8- 8- Brown 8- Brown
Exercise
• Making a Patch cable or Cross-over Cable.
http://www.rmfred.com/Wiring%20Guide/Wiring%20Guide.htm
Ethernet Cable Descriptions
• 100Base-TX• 1000Base-TX• 1000Base-SX• 1000Base-LX• 1000Base-CX• 10GBase-SR• 10GBase-LR• 10GBase-ER
Comparing Media
TechnologyTechnologyTransmissionTransmission
Distance Distance BandwidthBandwidthInstallationInstallation
EaseEaseConnectorConnector
TypeType
ThinNet 185 meters (600 feet) 10 Mbps Easy BNC
ThickNet 500 meters (1640 feet) 10 Mbps Difficult—Stiff cable Vampire taps
UTP 100 meters (320 feet) 10 Mbps to Gigabit Easy RJ-45
STP 90 meters (288 feet) 10 Mbps to Gigabit Difficult Specialized
Single-mode fiber Kilometers Gigabit and beyond Very difficult Specialized
Multimode fiber 2500 meters Gigabit Difficult SC and ST
Broadcast radio Up to 40 Kilometers 10 Mbps and up Easy
Infrared Short distances 10 Mbps and up Easy
Microwave Kilometers 10 Mbps and up Difficult
IEEE 1394 (FireWire)
• FireWire runs at 100, 200, 400Mbps (800Mbps in the 1394b standard), but in its standard mode it has a cable length limitation of 15 feet (4.5 meters),
A Fiber Optic Cable
Inner jacketInner jacket
Silica claddingSilica claddingOuter jacketOuter jacket
Glass or plastic coreGlass or plastic core
Fiber Optic Cable Mode Types
• Single-mode fiber• Step index multimode fiber• Graded index multimode fiber
Fiber Optic Connectors
ST SC FC
SMA
FDDI Mini-BNC Biconic
MT-RJLC
FireWire Connectors
Four-pinFour-pin Six-pinSix-pin
Plenum and PVC Cable
Unbounded Network Media
• Wireless communication• Radio Networking• Infrared Transmission• Microwave Transmission
• Signals transmitted as electromagnetic energy
• Enables users to move around • Can be point-to-point• Permits connections in areas
where it would be difficult to install wires
Wireless Communications
• Nondirectional; uses a single frequency for transmissions• Comes in low- and high-power versions • Low-power RF transmissions travel a short distance
– Inexpensive and relatively easy to install
• High-power RF transmissions travel considerably farther– Specially-trained technicians are often required to install
– More expensive type of system
Radio Networking
Infrared Transmission
Receiver
• Requires line of site
Satelite Transmission
Sender transmits electromagnetic signals
Sender transmits electromagnetic signals
Receiver has unobstructed view
Receiver has unobstructed view
• Requires line of site
Microwave Transmission
• Requires line of site
• Affects both bounded and unbounded network transmission.
• Unwanted signals that are introduced into network media.
Electrical Noise
Shielding
Secondary buffer to 900 µmSecondary buffer to 900 µm
Glass coreGlass corePrimary bufferPrimary buffer
Noise
Drain
Glass claddingGlass cladding
Differential Signaling
• Noise reduction technique in which the signals from two inputs are compared: signals that are identical on
the two inputs are ignored,
while those that are different on the inputs
are accepted
Noise Control with Twisted Pair
• Primary difference in cable categories is the number of twist per foot.
Termination
Terminator Terminator
Prevents signal reflection
Prevents signal reflection
– The bus must be terminated at both ends of the chain.
Grounding
Pipe connects to earth
Pipe connects to earth
Ground pointGround point ConductorConductor
Grounding
• Provides a means for noise to be drained off the line.
• Grounding refers to making a direct connection to the earth.
Media Installation Techniques
• Separate data and electric cables
• Fluorescent lights• Power ground• Connector installation
Network Interface Card Types
• Motherboard• USB • PC card• FireWire• Internal adapter card
A Transceiver on a Cable Modem Card
Transceiver chipTransceiver chip
A Transceiver on a Modem Card
Transceiver chipTransceiver chip
Premise Wiring
Rack in a wiring closetRack in a wiring closet
Patch cablePatch cable
Patch cablesPatch cables
Patch panelsPatch panels
A Repeater
Repeater
– A device that regenerates a signal to improve transmission distance.
A Hub
Hub
A Switch
Switch
Connects pairs of ports
Connects pairs of ports
A Bridge
Bridge
Divides network based on MAC
addresses
Divides network based on MAC
addresses
A Dedicated Router
Router
Divides network based on network
addresses
Divides network based on network
addresses
A Wireless Access Point
WAP
A Gateway
Gateway
LAN mediaLAN media WAN mediaWAN media
Network Standards
• Definition:– A set of specifications,
guidelines, or characteristics applied to network components to ensure interoperability and consistency between them.
Network standards
Number of computers
Connector type
Cable length
Standards Organizations
• ISO• IEEE• ANSI• TIA/EIA• IETF
Video:
• Warriors of the Net