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Chapter 2
Chapter 2: Basic Network Design and Protocols
Chapter 2: Basic Network Design and Protocols
Chapter 2
Learning ObjectivesLearning Objectives
Plan a networkPlan a network Explain network topologiesExplain network topologies Describe network communications mediaDescribe network communications media Explain how network cable connects to a Explain how network cable connects to a
computercomputer Describe the Ethernet and token ring Describe the Ethernet and token ring
transport methodstransport methods
continued
Chapter 2
Learning ObjectivesLearning Objectives
Describe Microsoft networking services Describe Microsoft networking services and protocolsand protocols
Determine how to select the topology Determine how to select the topology and communications cable for a given and communications cable for a given installationinstallation
Determine how to select the right Determine how to select the right protocol for a given installationprotocol for a given installation
Chapter 2
An Overview of NetworksAn Overview of Networks
Local area networks (LANs)Local area networks (LANs) Metropolitan area networks (MANs)Metropolitan area networks (MANs) Enterprise networksEnterprise networks Wide area networks (WANs)Wide area networks (WANs)
Chapter 2
An Overview of NetworksAn Overview of Networks
Local area networks (LANs)Local area networks (LANs) A series of interconnected computers, A series of interconnected computers,
printers, and other equipment that share printers, and other equipment that share hardware and software resourceshardware and software resources
Usually limited to a given floor, office area, Usually limited to a given floor, office area, or buildingor building
Chapter 2
A Sample LANA Sample LAN
Statistics lab
Business lab
Server
Chapter 2
An Overview of NetworksAn Overview of Networks
Metropolitan area networks (MANs)Metropolitan area networks (MANs) A network that links multiple LANs within a A network that links multiple LANs within a
large city or metropolitan regionlarge city or metropolitan region ex. Intel Oregon (Washington County)ex. Intel Oregon (Washington County)
• Jones Farm (Hillsboro)Jones Farm (Hillsboro)• Hawthorne Farm (Hillsboro)Hawthorne Farm (Hillsboro)• Cornell Oaks (Beaverton)Cornell Oaks (Beaverton)• Ronler Acres (Hillsboro)Ronler Acres (Hillsboro)• Aloha (Aloha)Aloha (Aloha)
Chapter 2
An Overview of NetworksAn Overview of Networks
Enterprise networksEnterprise networks A network that reaches throughout a large area A network that reaches throughout a large area
(e.g., cities, states) connecting many kinds of (e.g., cities, states) connecting many kinds of LANs and network resourcesLANs and network resources
Generally, privately-owned/leased wiresGenerally, privately-owned/leased wires
Wide area networks (WANs)Wide area networks (WANs) A far-reaching system of networks that can A far-reaching system of networks that can
extend across state lines and across continentsextend across state lines and across continents Slower links between sites (LANs)Slower links between sites (LANs)
Chapter 2
Enterprise Networks Connected into a WAN
Enterprise Networks Connected into a WAN
Toronto
Chicago
Detroit
Windows NT server IBM AS/400
Workstation Printer
Windows NT server Plotter
NetWare server
Workstation
Workstation
Mainframe
Production color laser printer
Telecommunications line
Network
Network
Network
Remote network connection
Supercomupter
Chapter 2
Planning a NetworkPlanning a Network
Size and purpose of organizationSize and purpose of organization Potential growth of the organization in Potential growth of the organization in
terms of people and servicesterms of people and services Number of mission-critical applications Number of mission-critical applications
on the networkon the network Important cycles for the businessImportant cycles for the business
continued
Chapter 2
Planning a NetworkPlanning a Network
Relationship of network resources to the Relationship of network resources to the mission of the businessmission of the business
Security needsSecurity needs Amount budgeted for network and Amount budgeted for network and
computer resourcescomputer resources
Chapter 2
Developing a PlanDeveloping a Plan
Number and kinds of workstations and Number and kinds of workstations and their operating systemstheir operating systems
Number and kinds of server and host Number and kinds of server and host computers and their operating systemscomputers and their operating systems
All software applications that will be All software applications that will be networkednetworked
continued
Chapter 2
Developing a PlanDeveloping a Plan
Characteristics of offices and the Characteristics of offices and the building layoutbuilding layout
Network management needsNetwork management needs Cabling types and topologiesCabling types and topologies
Chapter 2
Network TopologiesNetwork Topologies
TopologyTopology: the : the physicalphysical layout of a layout of a network combined with its network combined with its logical logical characteristicscharacteristics
Types of network topologiesTypes of network topologies BusBus RingRing StarStar Bus networks in a physical star layoutBus networks in a physical star layout
Chapter 2
Bus TopologyBus Topology
Nodes are connected to a segment of Nodes are connected to a segment of cable in the logical shape of a line, with cable in the logical shape of a line, with a terminator at each enda terminator at each end
node = network entity (computer, printer, etc.)node = network entity (computer, printer, etc.)
Network segment must adhere to IEEE Network segment must adhere to IEEE length specificationslength specifications
IEEE = Institute of Electrical and Electronics IEEE = Institute of Electrical and Electronics EngineersEngineers
Chapter 2
Bus TopologyBus Topology
Laptop computer
Terminator
Laser printer
File server
File server
Pen computer
TerminatorWorkstation
Workstation
Chapter 2
Bus TopologyAdvantages and Disadvantages
Bus TopologyAdvantages and Disadvantages
AdvantagesAdvantages Works well for small networksWorks well for small networks Relatively inexpensive to implementRelatively inexpensive to implement Easy to add another workstationEasy to add another workstation
DisadvantagesDisadvantages Potentially high management costsPotentially high management costs Can become congested with network trafficCan become congested with network traffic
Chapter 2
Ring TopologyRing Topology
A network in the form of a continuous A network in the form of a continuous ring, or circle, with nodes connected ring, or circle, with nodes connected around the ringaround the ring
A continuous path for data with no A continuous path for data with no logical beginning or ending point, thus logical beginning or ending point, thus no terminatorsno terminators
Chapter 2
Ring TopologyRing Topology
Workstation
Workstation
Workstation
File server
Ring
Chapter 2
Ring TopologyAdvantages and Disadvantages
Ring TopologyAdvantages and Disadvantages
AdvantagesAdvantages Easier to maintain than the busEasier to maintain than the bus Enables more reliable communications Enables more reliable communications
than the bus (distance and volume)than the bus (distance and volume) DisadvantagesDisadvantages
More expensive to implement than the busMore expensive to implement than the bus Not used as widely as the bus; fewer Not used as widely as the bus; fewer
options for equipment and expansionoptions for equipment and expansion
Chapter 2
Star TopologyStar Topology
Configured with a central hub and Configured with a central hub and individual cable segments connected to individual cable segments connected to the hub in the shape of a starthe hub in the shape of a star
Oldest communications design methodOldest communications design method
Chapter 2
Star TopologyStar Topology
Workstation
Workstation
Workstation Workstation
WorkstationHub
File server
Chapter 2
Star TopologyAdvantages and Disadvantages
Star TopologyAdvantages and Disadvantages
AdvantagesAdvantages Low startup costs (ex. share w/phone wire)Low startup costs (ex. share w/phone wire) Easier to manage than the busEasier to manage than the bus Easy to expandEasy to expand Widely used; variety of equipment availableWidely used; variety of equipment available
DisadvantagesDisadvantages Hub is a single point of failureHub is a single point of failure Requires more cable than bus designsRequires more cable than bus designs
Chapter 2
Bus Networks in a Physical Star Layout
Bus Networks in a Physical Star Layout
Combine logical communications of a bus Combine logical communications of a bus with physical layout of a starwith physical layout of a star
AdvantagesAdvantages No exposed terminatorsNo exposed terminators Multiple hubs can be connected for expansionMultiple hubs can be connected for expansion Popular alternative; wide range of equipment Popular alternative; wide range of equipment
availableavailable Compatible with bus protocols (Ethernet)Compatible with bus protocols (Ethernet)
Chapter 2
Expanding a Bus-star NetworkExpanding a Bus-star Network
Workstation
Hub
Hub
File server
Chapter 2
Network Communications MediaNetwork Communications Media
Coaxial cableCoaxial cable Thick coaxial cableThick coaxial cable Thin coaxial cableThin coaxial cable
Twisted-pair cableTwisted-pair cable Shielded twisted-pair cable (STP)Shielded twisted-pair cable (STP) Unshielded twisted-pair cable (UTP)Unshielded twisted-pair cable (UTP)
Fiber-optic cableFiber-optic cable
Chapter 2
Characteristics of Network Communications Media
Characteristics of Network Communications Media
Data transfer speedData transfer speed Use in specific network topologiesUse in specific network topologies Distance requirementsDistance requirements Cable and cable component costsCable and cable component costs Additional network equipment requiredAdditional network equipment required Ease of installationEase of installation Immunity to interference from outside sourcesImmunity to interference from outside sources Upgrade optionsUpgrade options
Chapter 2
Thick Coaxial CableThick Coaxial Cable
Used on early networks, particularly as a Used on early networks, particularly as a backbone to join different networksbackbone to join different networks
AdvantagesAdvantages Durable and reliableDurable and reliable Great resistance to signal interferenceGreat resistance to signal interference
DisadvantagesDisadvantages Difficult to manipulate and terminateDifficult to manipulate and terminate Expensive to purchase and installExpensive to purchase and install
Chapter 2
Thick Coaxial CableThick Coaxial Cable
Copper center conductor
Conductor insulation
Aluminum sleeve
PVC or Teflon jacket
Chapter 2
Thin Coaxial CableThin Coaxial Cable
Used in networks to connect Used in networks to connect desktops/workstations, and serversdesktops/workstations, and servers
Easy and cheap to installEasy and cheap to install
A T-connector with a terminator at one endA T-connector with a terminator at one end
BNC T-connector
BNC connector
Terminator
Chapter 2
Twisted-pair CableTwisted-pair Cable
Most popular communications mediumMost popular communications medium More flexible than coax for running More flexible than coax for running
through walls and around cornersthrough walls and around corners Can be adapted for high speed Can be adapted for high speed
communicationscommunications Connectors are less expensive, less Connectors are less expensive, less
susceptible to damage, and easy to susceptible to damage, and easy to connectconnect
Chapter 2
Shielded Twisted-Pair CableShielded Twisted-Pair Cable
Shielding reduces interruptions of the Shielding reduces interruptions of the communication signal caused by communication signal caused by electrical interferenceelectrical interference
Plastic encasement
ShieldingColor-coded
insulationCopper wire conductor
Chapter 2
Unshielded Twisted-pair CableUnshielded Twisted-pair Cable
Most frequently used because of low Most frequently used because of low cost, relatively easy installation, and cost, relatively easy installation, and high reliabilityhigh reliability
Plastic encasement
Color-coded insulation
Copper wire conductor
Chapter 2
Fiber-optic CableFiber-optic Cable
AdvantagesAdvantages Able to carry large amounts of data over Able to carry large amounts of data over
long distanceslong distances No problem with electrical interferenceNo problem with electrical interference Difficult for unauthorized taps to be placedDifficult for unauthorized taps to be placed
DisadvantagesDisadvantages Very fragile and relatively expensiveVery fragile and relatively expensive Requires specialized training to installRequires specialized training to install
Chapter 2
Fiber-optic CableFiber-optic Cable
Single-mode transmissionSingle-mode transmission just one wavelength (color) of lightjust one wavelength (color) of light simpler (therefore cheaper) hardwaresimpler (therefore cheaper) hardware
Multi-mode transmissionMulti-mode transmission several wavelengths (colors) at a timeseveral wavelengths (colors) at a time carries much more informationcarries much more information more complex hardware (therefore more more complex hardware (therefore more
expensive)expensive) frequently used for “backbone” connectionsfrequently used for “backbone” connections
Chapter 2
Fiber-optic CableFiber-optic Cable
Optical fiber (core)
Glass claddingProtective outer sheath (jacket)
Chapter 2
Network Interface Card (NIC)Network Interface Card (NIC)
Connects a workstation, file server, or other Connects a workstation, file server, or other network equipment to communications cablenetwork equipment to communications cable
Contains a transceiverContains a transceiver for sending and for sending and receiving data signalsreceiving data signals
Software drivers encode and decode dataSoftware drivers encode and decode data Built-in memory chips provide temporary Built-in memory chips provide temporary
storagestorage Designed for coaxial, twisted-pair, or fiber-optic Designed for coaxial, twisted-pair, or fiber-optic
cablecable
Chapter 2
Connecting Cable to a NICConnecting Cable to a NIC
Connector just liketelephone connector(RJ-11, four wire;RJ-45, eight wire).
Chapter 2
Transporting Data on the Communications Cable
Transporting Data on the Communications Cable
EthernetEthernet Used more often than token ringUsed more often than token ring Offers more network design optionsOffers more network design options Offers more high-speed networking options Offers more high-speed networking options More widely supported by network devicesMore widely supported by network devices
Token ringToken ring Highly reliable network communications, Highly reliable network communications,
particularly on busy networksparticularly on busy networks
Chapter 2
EthernetEthernet
Typically implemented in bus or star (or Typically implemented in bus or star (or combined) topologycombined) topology
Uses the CSMA/CD (Carrier Sense Uses the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) Multiple Access with Collision Detection) access method for data transmission on a access method for data transmission on a networknetwork
Originally, 10Mbps (megabits/sec); now Originally, 10Mbps (megabits/sec); now 100Mbps and up to Gbps speeds available100Mbps and up to Gbps speeds available
Chapter 2
ProtocolsProtocols
NetBIOS (Network Basic Input/Output System)NetBIOS (Network Basic Input/Output System) NetBEUI (NetBIOS Extended User Interface)NetBEUI (NetBIOS Extended User Interface) NDIS (Network Driver Interface Specification)NDIS (Network Driver Interface Specification) NWLink (NetWare Link)NWLink (NetWare Link) ODI (Open Datalink Interface)ODI (Open Datalink Interface) TCP/IP (Transmission Control Protocol/Internet TCP/IP (Transmission Control Protocol/Internet
Protocol)Protocol) DLC (Data Link Control Protocol)DLC (Data Link Control Protocol) AppleTalkAppleTalk
Chapter 2
Microsoft Tools for Ethernet and Token Ring Communications
Microsoft Tools for Ethernet and Token Ring Communications
Service Function
NetBIOS A link to programs that use the NetBIOSinterface
NetBEUI Software drivers for a data transport protocolused on small Microsoft-based networks
NDIS A specification for, and software drivers toenable, Microsoft-based network protocols tocommunicate with a NIC
ODI Novell-developed software drivers forcommunications with Novell NetWare networks
continued
Chapter 2
Microsoft Tools for Ethernet and Token Ring Communications
Microsoft Tools for Ethernet and Token Ring Communications
Service Function
NWLink Microsoft-developed drivers for communica-tions with Novell NetWare networks
TCP/IP Software drivers for TCP/IP communicationswith mainframes, UNIX computers, and Internetservers
DLC Software drivers for communications with IBMmainframes and minicomputers
AppleTalk Software drivers for communications with AppleMacintosh computers
Chapter 2
Protocol StackProtocol Stack
continued
Driver is lowest-levelDriver is lowest-level runs in kernelruns in kernel we’ll cover this more laterwe’ll cover this more later
Protocol(s) nextProtocol(s) next TCP/IP, SPX/IPX, NetBEUI, etc.TCP/IP, SPX/IPX, NetBEUI, etc.
““Client”(s) nextClient”(s) next Client for Microsoft Networks (uses NetBEUI)Client for Microsoft Networks (uses NetBEUI) Novell NetWare or MS Client for NetWareNovell NetWare or MS Client for NetWare Applications (SMTP, HTTP, FTP, telenet…)Applications (SMTP, HTTP, FTP, telenet…)
Akin to “7-layer model” but not exactlyAkin to “7-layer model” but not exactly
Chapter 2
NetBIOSNetBIOS
A combination software interface and A combination software interface and network naming conventionnetwork naming convention
Available in Microsoft operation systems Available in Microsoft operation systems through the file NETBIOS.DLLthrough the file NETBIOS.DLL
Chapter 2
NetBIOS/NetBEUI Communications
NetBIOS/NetBEUI Communications
Sent onto the network
(Transport driver)
Started NetBIOS-compatible application
NetBIOS software interface
NetBEUI protocol
Chapter 2
NetBEUINetBEUI
Well-suited for small LANs using Well-suited for small LANs using Microsoft or IBM operating systemsMicrosoft or IBM operating systems Simple to installSimple to install Compatible with Microsoft workstation and Compatible with Microsoft workstation and
server operating systemsserver operating systems Nearly limitless communication sessions on Nearly limitless communication sessions on
one networkone network Low memory requirements; can be quickly Low memory requirements; can be quickly
transported over small networkstransported over small networks
Chapter 2
NDISNDIS
A set of standards developed by A set of standards developed by Microsoft for network driversMicrosoft for network drivers
Enables communication between a NIC Enables communication between a NIC and a protocoland a protocol
Enables use of multiple protocols on Enables use of multiple protocols on same networksame network
Chapter 2
Binding a Protocol to a NICBinding a Protocol to a NIC
Network protocol (such as NetBEUI)
NDIS driver
Network interface card (NIC)
Chapter 2
ODIODI
Open data-link interfaceOpen data-link interface A driver that is used by Novell NetWare A driver that is used by Novell NetWare
networks to transport multiple protocols networks to transport multiple protocols on the same networkon the same network
Chapter 2
NWLinkNWLink
A network protocol that simulates the A network protocol that simulates the IPX/SPX protocol for Microsoft Windows IPX/SPX protocol for Microsoft Windows 95 and NT communications with Novell 95 and NT communications with Novell NetWare file servers and compatible NetWare file servers and compatible devicesdevices
Chapter 2
NWLinkAdvantages and Disadvantages
NWLinkAdvantages and Disadvantages
AdvantagesAdvantages Has routing capabilities over enterprise networksHas routing capabilities over enterprise networks Easy to installEasy to install More effective communications with NetWare file More effective communications with NetWare file
servers than the ODI driverservers than the ODI driver DisadvantagesDisadvantages
Not transported as fast as NetBEUINot transported as fast as NetBEUI A “chatty” protocol - each packet transmitted must A “chatty” protocol - each packet transmitted must
be acknowledged by the receiving nodebe acknowledged by the receiving node
Chapter 2
TCP/IPTCP/IP
TCP portion performs extensive error TCP portion performs extensive error checking to ensure that data are checking to ensure that data are delivered successfullydelivered successfully
TCP == “transmission control protocol”TCP == “transmission control protocol”
IP portion consists of rules for IP portion consists of rules for packaging data and ensuring that is packaging data and ensuring that is reaches the correct destination addressreaches the correct destination address
IP == “Internet protocol”IP == “Internet protocol”
Chapter 2
TCP/IP AdvantagesTCP/IP Advantages
Well-suited for medium and large networksWell-suited for medium and large networks Designed for routing; has high degree of Designed for routing; has high degree of
reliabilityreliability Used worldwide for directly connecting to the Used worldwide for directly connecting to the
Internet and by Web serversInternet and by Web servers Compatible with standard tools for analyzing Compatible with standard tools for analyzing
network performancenetwork performance Includes ability to use DHCP and WINS Includes ability to use DHCP and WINS
through a Microsoft NT serverthrough a Microsoft NT server
Chapter 2
TCP/IP DisadvantagesTCP/IP Disadvantages
More difficult to set up and maintain More difficult to set up and maintain than NetBEUI or IPX/SPXthan NetBEUI or IPX/SPX
but frequently worth the painbut frequently worth the pain
Can be slower than IPX/SPX and Can be slower than IPX/SPX and NetBEUI on networks with light to NetBEUI on networks with light to medium trafficmedium traffic
Chapter 2
Protocols Associatedwith TCP/IP
Protocols Associatedwith TCP/IP
TelnetTelnet Provides terminal emulation servicesProvides terminal emulation services
File Transfer Protocol (FTP)File Transfer Protocol (FTP) Enables files to be transferred across a network or the Enables files to be transferred across a network or the
InternetInternet Simple Mail Transfer Protocol (SMTP)Simple Mail Transfer Protocol (SMTP)
An e-mail protocolAn e-mail protocol Domain Name Service (DNS)Domain Name Service (DNS)
Resolves domain computer names to IP addresses or Resolves domain computer names to IP addresses or vice versavice versa
Chapter 2
Connecting to IBM Mainframes with DLC
Connecting to IBM Mainframes with DLC
Enables communications with an IBM Enables communications with an IBM mainframe or minicomputermainframe or minicomputer
AdvantageAdvantage An alternative to TCP/IPAn alternative to TCP/IP
DisadvantagesDisadvantages Not routableNot routable Not truly designed for peer-to-peer Not truly designed for peer-to-peer
communications between workstationscommunications between workstations
Chapter 2
Connecting to Macintosh Computers with AppleTalkConnecting to Macintosh
Computers with AppleTalk
A peer-to-peer protocol used on A peer-to-peer protocol used on networks for communications between networks for communications between Macintosh computersMacintosh computers
Supported in very limited ways on non-Supported in very limited ways on non-Macintosh networksMacintosh networks
Chapter 2
Selecting the Right Topology and Communications Cable
Selecting the Right Topology and Communications Cable
Network topology selection depends on Network topology selection depends on the size and needs of your networkthe size and needs of your network
Cable selection depends on the Cable selection depends on the physical topologyphysical topology
Chapter 2
Selecting the Right ProtocolSelecting the Right Protocol
Do frames need to be routed?Do frames need to be routed? Is the network small, medium, or large?Is the network small, medium, or large? Are there Microsoft NT servers?Are there Microsoft NT servers? Are there mainframe host computers?Are there mainframe host computers? Are there NetWare servers?Are there NetWare servers? Is there direct access to the Internet or to Is there direct access to the Internet or to
Web-based intranet applications?Web-based intranet applications? Are there mission-critical applications?Are there mission-critical applications?
Chapter 2
Chapter SummaryChapter Summary
A Windows NT server operates in the A Windows NT server operates in the context of a network.context of a network. LAN, enterprise, WANLAN, enterprise, WAN Factors in preparing a networkFactors in preparing a network
Needs of organizationNeeds of organization Software that will be usedSoftware that will be used Existing computer equipmentExisting computer equipment Security requirementsSecurity requirements
continued
Chapter 2
Chapter SummaryChapter Summary
Network design employs the bus, ring, Network design employs the bus, ring, and star topologies.and star topologies.
Communications cable includes coax, Communications cable includes coax, twisted-pair, and fiber-optic cable.twisted-pair, and fiber-optic cable.
continued
Chapter 2
Chapter SummaryChapter Summary
Network communications are enabled Network communications are enabled through network transport methods through network transport methods such as Ethernet and token ring.such as Ethernet and token ring. Ethernet offers expansion and high-speed Ethernet offers expansion and high-speed
networking optionsnetworking options Token ring offers reliable communications Token ring offers reliable communications
and time-proven technologyand time-proven technology
continued
Chapter 2
Chapter SummaryChapter Summary
Protocols such as NetBEUI and TCP/IP Protocols such as NetBEUI and TCP/IP establish a communications format that establish a communications format that is understood by the computers on a is understood by the computers on a network.network.
Microsoft networks support many Microsoft networks support many different protocols for different network different protocols for different network sizes and requirements.sizes and requirements.