Chapter 1

 Upon completion of this chapter, you should be able to:  Define & identify different types of networks  Describe the advantages & disadvantages of network types  Describe & identify topologies  Identify the OSI model, why it’s used, and what happens at each layer  Describe various protocols  Compare and contrast TCP and UDP  Convert binary to decimal to hexadecimal

1.1

 What is a network?  Group of interconnected devices able to share info with each other  Networks consist of:  Hosts/Nodes  Connecting Media  Network interface  Protocols (standards)

 Share peripherals  Consolidate storage  Group collaboration/communication  File sharing, , social media, VoIP, websites

 Hosts don’t have a specific role  Can provide & consume network services

ADVANTAGESDISADVANTAGES  Easy to implement  Inexpensive to implement  No special software to buy; use PC’s OS  Easy to configure to share storage & printing  Not scalable  Bigger = difficult to manage  Usually limited to 10  No centralized controls  Decentralized storage  Possible slower performance

 Server  Provides a resource/service, like or web pages server/web server  Client  Consumes network services  Requests & displays info from a server PC with web browser to display pages from web server

ADVANTAGESDISADVANTAGES  Very scalable  Easy to support  Centralized management  Data protection  Backup shared data on server  More expensive!  Advanced planning to setup

 Addressing  Subnet  LAN  MAN  WAN  Internet  Intranet  Extranet Test Out Watch video & take notes 10:58

 Over a small area

 Connected networks  Not owned by anyone  Organizations maintain it & standards

 What type of network uses each device to share files with other devices on the network?  Peer to peer  What type of network do you assign specific hosts a role such as file storage and other hosts just access those resources?  Client-server  What connects a client PC to the network’s medium?  Network interface

1.2

 Graphical layout of the network  Two types:  Physical topology Layout of how devices are physically connected  Logical topology How devices communicate/data transmitted Shows IP addresses & groups

 Bus/Broadcast  Data sent to ALL devices connected to the cable  Each device looks at the data to see if it is addressed to it or not  Ring  Data is passed from computer to computer  Star  Data sent only to destination device

 Bus  All connected to same cable, terminated at end  Broken cable= no one communicates  Ring  Each device connected to each other

 Has a central connecting device  Most common

 Each device connects to every other device  Redundancy  Used in backbone; not with PCs

 Physical & logical topology ID handout

 The physical layout of nodes on a network is known as the networks:  Topology  Which physical topology is most common today?  Star  How does data get passed in a logical ring topology?  Sent from one device to the next  How does data get passed in a logical bus topology?  Sent to all devices in network

1.3

 Before 1983, network devices were proprietary  Had to buy all from same vendor or it wouldn’t work  OSI model created standards to follow  OSI model layers break down the communication process between devices

Layer #Layer NameDescription 7Application Provides network access to applications SMTP; HTTP; DHCP; FTP; Telnet 6PresentationTransforms data to a format 5SessionEstablishes, manages, terminates sessions 4Transport Reliable transport; flow control; retransmission; TCP; port numbers; segments 3NetworkRouting; Logical (IP) addressing; packet 2Data Link Physical (MAC) addressing; access to media frame 1PhysicalBits; electricity

 The OSI Communications Process  Go to Test Out  View &  Review OSI Model Facts  Exam Questions

1.4

 Encoding  Converting info for travel on media  Ex: bits into electricity, light, radio waves  Types of Signals:  Digital (bits) 0 volts= 0 +5 volts= 1  Analog Doesn’t represent bits But can be converted…

 Converting digital signal to analog  Connect via phone line  FM (Frequency Modulation)  Varies the frequency (or hertz)  AM (Amplitude Modulation)  Adjusts the strength

 Converting analog to digital  Modem (modulate-demodulate)  Baud- # time per second signal changes  Bit Rate- # of bits per second

 Analog signals over multiple frequencies  Uses Multiplexing Mixing multiple signals over a cable’s bandwidth Usually outside of your network

 Sends data in single channel using all bandwidth of the cable (one at a time)  Uses Time-Division Multiplexing  Each signal gets a specific time to send  Ethernet is baseband  Send/receive using all of the frequency

 Quiz  What is the process for converting digital signals for travel on media?  Encoding  What is the process of converting signals on media to digital?  Decoding  What process allows multiple signals to be mixed over a cable’s bandwidth?  Multiplexing

1.5

 What is a protocol?  Set of rules for communication  Protocol Suite  Set of protocols that work together  TCP/IP

 Connection-oriented  Sends acknowledgements  Like tracking a FedEx delivery  Breaks messages into small segments  If sender doesn’t get an ACK of message received, it retransmits  Only portion lost is resent  On receiving host, TCP reassembles data  FTP & HTTP are examples of protocols using TCP

 Connectionless  Used for faster transmissions  Low overhead  “Best effort delivery”  Regular mail / no guarantee of delivery  No ACK or retransmission  No error checking*  Used for streaming audio, video, VoIP  DNS, DHCP, TFTP, VoIP, Gaming, SNMP are examples of protocols that use UDP

TCPUDP  Guaranteed delivery  Connection-oriented  Acknowledgements  Slower bc of establishing a connection & acknowledging  , web, file transfer  Best effort delivery  Connectionless  No acknowledgements  Faster bc of no connection or acknowledgements  Audio/video streams

ProtocolInformation HTTP Connection to transfer web pages- TCP HTTPS Secure connection for web pages transmission- TCP Security created by SSL or TSL FTP File transfer- TCP TFTP File transfer- UDP Telnet Remote login- TCP SSH Secure remote login- TCP POP3 Transfer of from server to you; then deleted IMAP Transfer of from server to you; kept on server SMTP Used to send between servers

ProtocolInformation SFTP & SCP Secure file transfer DHCP Automatically assign IP/SM/DG/DNS server addresses- UDP DNS Translates names to IP addresses- TCP/UDP NTP Allows devices to sync their clocks through network- TCP/UDP SNMP Create alerts to monitor the network- UDP ICMP Can detect other devices & verify connectivity- PING

 Review all protocols on  Take Quiz on 1.5.5

 Web server  FTP server  DNS server  DHCP server  Directory Services  Directory of users on a network, resources, and access control  SSH Server  From client, you can connect remotely & securely to a device Review Review

 What type of network has centralized resources, such as central file storage?  Client-server  What type of network shares resources located on local computer hard drives?  Peer to peer  You type into your web browser. A DNS request is created and then a we request is sent. What type of network is this?  Client-server

 Which protocol is used for web page transmission?  HTTP  You have a network of 100 devices. Which process will easily allow all computers to automatically be able to communicate on a network by assigning IP addresses?  DHCP  Which utility/protocol can test connectivity?  Ping/ICMP  Which protocol allows remote login, but is not secure?  Telnet

1.6

 Add up the values of the binary 1’s  156  

 Binary to Decimal Conversions  Add up the bit values to come up with the decimal answer  Decimal to Binary Conversions  Convert the decimal number to bits  Binary Game  Play Now Play Now

 Hex= MAC address  0-9, A-F (10-15)  Convert Hex to Binary, then to Decimal  Convert backwards too  AB

 TestOut Quiz  Conversion Handout/Quiz

 Complete the study guide handout  Take all quizzes on TestOut  Jeopardy review

Chapter 1