Networking Basics Networking Basics Lesson 1 Introduction to Networks
Networking BasicsNetworking Basics
Lesson 1
Introduction to Networks
Introduction to NetworksIntroduction to Networks
What is Networking?What is Networking? Networks EnvironmentsNetworks Environments
StandaloneStandalone
NetworkingNetworking LANs Vs WANsLANs Vs WANs
Network definitionNetwork definition
data network is a group of computers data network is a group of computers connected by a network medium. connected by a network medium.
The network medium carries signals The network medium carries signals between computers.between computers.
Signals reduce complex information to the Signals reduce complex information to the simplest possible form.simplest possible form.
Computers communicate by using a Computers communicate by using a language called a protocol.language called a protocol.
Protocol ServicesProtocol Services
Packet acknowledgmentPacket acknowledgment SegmentationSegmentation Flow controlFlow control Error detectionError detection Error correctionError correction Data compressionData compression Data encryptionData encryption
Networks EnvironmentsNetworks Environments
StandaloneStandalone
Networks EnvironmentsNetworks Environments
NetworkingNetworking
Networking BenefitsNetworking Benefits
Sharing Resources Sharing Resources InformationInformation HardwareHardware SoftwareSoftware
Fault ToleranceFault Tolerance Protecting InformationProtecting Information E-mailE-mail
Network Primary TypesNetwork Primary Types
Local Area Networks (LANs)Local Area Networks (LANs)
Wide Area Networks (WANs)Wide Area Networks (WANs)
LANLAN
local area network (LAN) is a collection of local area network (LAN) is a collection of computers located in a relatively small area and computers located in a relatively small area and connected by a common medium.connected by a common medium.
The pattern in which computers in a LAN are The pattern in which computers in a LAN are connected is called the topology.connected is called the topology.
LAN topologies include bus, star, and ring.LAN topologies include bus, star, and ring. The defining protocols for a LAN are the data-The defining protocols for a LAN are the data-
link layer protocols.link layer protocols.
Wide Area NetworkWide Area NetworkA WAN uses an external network A WAN uses an external network
provider to connect LANsprovider to connect LANs..
Example of WAN networkExample of WAN network
EX. Of WAN Frame RelayEX. Of WAN Frame Relay
A packet-switching protocol for connecting A packet-switching protocol for connecting devices on a Wide Area Network (WAN)devices on a Wide Area Network (WAN)
Frame Relay networks support data Frame Relay networks support data transfer rates at T-1 (1.544 Mbps) and T-3 transfer rates at T-1 (1.544 Mbps) and T-3 (45 Mbps) speeds(45 Mbps) speeds
Most telephone companies now provide Most telephone companies now provide Frame Relay service for customers who Frame Relay service for customers who want connections at 56 Kbps to T-1 want connections at 56 Kbps to T-1 speeds speeds
ATMATM
Short for Asynchronous Transfer ModeShort for Asynchronous Transfer Mode technology based on transferring data in cells or technology based on transferring data in cells or
packets of a fixed sizepackets of a fixed size Creates a fixed channel, or route, between two Creates a fixed channel, or route, between two
points whenever data transfer begins (Point to points whenever data transfer begins (Point to Point)Point)
Needs special ATM Device in both network, Needs special ATM Device in both network, sending & receiving sending & receiving
Rarely usedRarely used
A backbone network connects A backbone network connects segments together, forming an segments together, forming an
internet workinternet work..
Administrator Administrator ResponsibilityResponsibility
SecuritySecurity Resources AdministratingResources Administrating Applications & Data MaintainingApplications & Data Maintaining Installation & upgrading Installation & upgrading
Network RequirementsNetwork Requirements
Connections (NIC, Medium)Connections (NIC, Medium) Communication (Protocol)Communication (Protocol) Services Services
Roles of Computers in a Roles of Computers in a networknetwork
ClientsClients Request OnlyRequest Only
ServersServers Reply to Requests OnlyReply to Requests Only
PeersPeers Request & ReplyRequest & Reply
Network TypesNetwork Types
Peer to PeerPeer to Peer No Dedicated ServerNo Dedicated Server
Server BasedServer Based Dedicated Servers & ClientsDedicated Servers & Clients
CentralizedCentralized Dump TerminalDump Terminal
Peer to Peer NetworkPeer to Peer Network
WorkgroupWorkgroup No Central Logon (Local Account)No Central Logon (Local Account)
No Specific OSNo Specific OS
Advantages of Peer to PeerAdvantages of Peer to Peer
No Extra Investment for Hardware or No Extra Investment for Hardware or SoftwareSoftware
Easy SetupEasy Setup No Administrator requiredNo Administrator required Users control what to share Users control what to share No reliance on other computersNo reliance on other computers Lower Cost for small networks (10 users) Lower Cost for small networks (10 users)
Disadvantages of Peer to Disadvantages of Peer to PeerPeer
Additional Load on PCsAdditional Load on PCs Inability to handle many network Inability to handle many network
connections as serversconnections as servers Lack of Central OrganizationLack of Central Organization User should administer their own User should administer their own
computerscomputers Weak securityWeak security
Server Based NetworksServer Based Networks
Domain ModelDomain Model PDC/BDCPDC/BDC Active DirectoryActive Directory
Advantages of Server Based Advantages of Server Based NetworksNetworks
Strong SecurityStrong Security Central File StorageCentral File Storage Share Expensive EquipmentShare Expensive Equipment Dedicated Servers are optimized for their Dedicated Servers are optimized for their
jobjob Users don’t bother managing the network Users don’t bother managing the network
Advantages of Server Based Advantages of Server Based Networks [Cont.]Networks [Cont.]
Single Password allows access to all Single Password allows access to all shared resources depending on shared resources depending on permissionspermissions
Central organizationCentral organization Easy Manageable for large numbers of Easy Manageable for large numbers of
users users
Disadvantages of Server Based Disadvantages of Server Based NetworksNetworks
Expensive Dedicated HardwareExpensive Dedicated Hardware Expensive Network OSExpensive Network OS A dedicated Network Administrator A dedicated Network Administrator
Centralized NetworkCentralized Network
Using Dump-TerminalUsing Dump-Terminal
Server TypesServer Types
File & Print ServerFile & Print Server Database Servers (Application Server)Database Servers (Application Server) Mail ServersMail Servers Fax ServersFax Servers Directory Service Server (Active Directory)Directory Service Server (Active Directory)