Chapter 2 Chapter 2: Basic Network Design and Protocols.

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.