itn instructorppt chapter3

Chapter 3:Network Protocols andNetwork Protocols and Communications

Introduction to Networks

2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 1

Chapter 3: Objectives

Students will be able to:

Explain how rules are used to facilitate communication.E l i th l f t l d t d d Explain the role of protocols and standards organizations in facilitating interoperability in network communicationscommunications.

Explain how devices on a LAN access resources in a ll t di i d b i t ksmall to medium-sized business network.

Presentation_ID 2 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential

Chapter 33 1 R l f C i ti3.1 Rules of Communication3.2 Network Protocols and Standards3.3 Moving Data in the Network3 4 Summary3.4 Summary


The RulesWhat is Communication?


The RulesEstablishing the RulesE t bli hi th R lEstablishing the Rules

An identified sender and receiver An identified sender and receiver Agreed upon method of communicating (face-to-face,

telephone, letter, photograph)

Common language and grammarCommon language and grammar Speed and timing of delivery Confirmation or acknowledgement requirements


The RulesMessage Encoding


The RulesMessage Formatting and EncapsulationE l P l l tt t i th f ll i l tExample: Personal letter contains the following elements:

An identifier of the recipientp A salutation or greeting The message content A closing phraseA closing phrase An identifier of the sender


The RulesMessage SizeTh i t i ti f f i th h t t b kThe size restrictions of frames require the source host to break a long message into individual pieces that meet both the minimum and maximum size requirementsminimum and maximum size requirements.

This is known as segmenting.

Each segment is encapsulated in a separate frame with the address information, and is sent over the network. ,

At the receiving host, the messages are de-encapsulated and put back together to be processed and interpretedput back together to be processed and interpreted.


The RulesMessage Timing

A M th d Access Method Flow Control Response Timeout


The RulesMessage Delivery Options


ProtocolsRules that Govern Communications


ProtocolsNetwork Protocols

H th i f tt d t t d How the message is formatted or structured The process by which networking devices share information p y g

about pathways with other networks

How and when error and system messages are passedHow and when error and system messages are passed between devices

Th t d t i ti f d t t f i The setup and termination of data transfer sessions


ProtocolsInteraction of Protocols

A li ti P t l H t t T f P t l (HTTP) Application Protocol Hypertext Transfer Protocol (HTTP) Transport Protocol Transmission Control Protocol (TCP)p ( ) Internet Protocol Internet Protocol (IP) Network Access Protocols Data Link & Physical layers


Protocol SuitesProtocol Suites and Industry Standards


Protocol SuitesCreation of Internet, Development of TCP/IP


Protocol SuitesTCP/IP Protocol Suite and Communication


Network Protocols and StandardsStandards Organizations


Standards OrganizationsOpen Standards

Th I t t S i t (ISOC) The Internet Society (ISOC) The Internet Architecture Board (IAB)( ) The Internet Engineering Task Force (IETF) Institute of Electrical and Electronics Engineers (IEEE) The International Organization for Standards (ISO)The International Organization for Standards (ISO)


Standards OrganizationsISOC, IAB, and IETF


Standards OrganizationsIEEE

38 i ti 38 societies 130 journalsj 1,300 conferences each year 1,300 standards and projects 400,000 members400,000 members 160 countries IEEE 802.3 IEEE 802 11 IEEE 802.11


Standards OrganizationsISO


Standards OrganizationsOther Standards Organization

Th El t i I d t i Alli (EIA) The Electronic Industries Alliance (EIA) The Telecommunications Industry Association (TIA)y ( ) The International Telecommunications Union

Telecommunications Standardization Sector (ITU-T)Telecommunications Standardization Sector (ITU T)

The Internet Corporation for Assigned Names and Numbers (ICANN)(ICANN)

The Internet Assigned Numbers Authority (IANA)g y ( )


Reference ModelsThe Benefits of Using a Layered Model


Reference ModelsThe OSI Reference Model


Reference ModelsThe TCP/IP Reference Model


Reference ModelsComparing the OSI and TCP/IP Models


Data EncapsulationCommunicating the Messages

S ti b fit Segmenting message benefitsDifferent conversations can be interleavedIncreased reliability of network communications

Segmenting message disadvantageIncreased level of complexityIncreased level of complexity


Data EncapsulationProtocol Data Units (PDUs)

D t Data Segmentg Packet Frame BitsBits


Data EncapsulationEncapsulation


Data EncapsulationDe-encapsulation


Moving Data in the NetworkAccessing Local Resources


Accessing Local ResourcesNetwork Addresses & Data Link addresses

N t k Add Network AddressSource IP addressDestination IP address

Data Link AddressSource data link addressSource data link addressDestination data link address


Accessing Local ResourcesCommunicating with Device / Same Network


Accessing Local ResourcesMAC and IP Addresses

R1R1192.168.1.1

11-11-11-11-11-11ARP

RequestPC1

192.168.1.110AA-AA-AA-AA-AA-AA

qS1 R1

PC2192 168 1 111192.168.1.111

BB-BB-BB-BB-BB-BB

FTP Server192.168.1.9

CC-CC-CC-CC-CC-CC


Accessing Remote ResourcesDefault Gateway

PC 1 R2PC 1192.168.1.110

AA-AA-AA-AA-AA-AA

R1192.168.1.1

11-11-11-11-11-11

172.16.1.9922-22-22-22-22-22

Web Server172.16.1.99

AB-CD-EF-12-34-56

PC 2 FTP Server192 168 1 9192.168.1.111

BB-BB-BB-BB-BB-BB192.168.1.9

CC-CC-CC-CC-CC-CC


Accessing Remote ResourcesCommunicating Device / Remote Network


Accessing Remote ResourcesUsing Wireshark to View Network Traffic


Network Protocols and CommunicationsSummaryI thi h t l dIn this chapter, you learned:

Data networks are systems of end devices, intermediary y ydevices, and the media connecting the devices. For communication to occur, these devices must know how to communicate.

These devices must comply with communication rules and p yprotocols. TCP/IP is an example of a protocol suite.

Most protocols are created by a standards organization such Most protocols are created by a standards organization such as the IETF or IEEE.

The most widely-used networking models are the OSI and TCP/IP models.



Data that passes down the stack of the OSI model is psegmented into pieces and encapsulated with addresses and other labels. The process is reversed as the pieces are de-encapsulated and passed up the destination protocol stack.

The OSI model describes the processes of encoding, p g,formatting, segmenting, and encapsulating data for transmission over the network.

The TCP/IP protocol suite is an open standard protocol that has been endorsed by the networking industry and ratified orhas been endorsed by the networking industry and ratified, or approved, by a standards organization.



The Internet Protocol Suite is a suite of protocols required for p qtransmitting and receiving information using the Internet.

Protocol Data Units (PDUs) are named according to theProtocol Data Units (PDUs) are named according to the protocols of the TCP/IP suite: data, segment, packet, frame, and bits.

Applying models allows individuals, companies, and trade associations to analyze current networks and plan theassociations to analyze current networks and plan the networks of the future.


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