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01 basico redes 01 basico redes Presentation Transcript

  • Module 1:Internetworking Basics
  • Before begin…
  • Cisco Icons and Symbols: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-3
  • Cisco Icons and Symbols: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-4
  • Computer Basics PC COMPONENTS PC’s are the building block of the networks. They have many of the same parts and systems as the other network devices, such as router and switches. You should understand the functions of the following components in case the need to troubleshooting arises.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-5
  • CPU: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-6
  • Expansion Slot: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-7
  • Floppy Disk Drive: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-8
  • Motherboard: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-9
  • PC Vs. Laptop: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-10
  • Network Interface Card: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-11
  • NIC Installation: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-12
  • Units Information: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-13
  • Base 2 Numbering System: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-14
  • Binary-to-Decimal Conversion: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-15
  • Base 2 Number System: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-16
  • Binary And Decimal Translation 10011101 2 7 2 6 2 5 2 4 2 3 2 2 2 1 2 0 128 64 32 16 8 4 2 1 128+16+8+4+1= 157: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-17
  • Binary And Decimal Translation Decimal Hexadecimal Binary 0 0 0000 1 1 0001 2 2 0010 3 3 0011 4 4 0100 5 5 0101 6 6 0110 7 7 0111 8 8 1000 9 9 1001 10 A 1010 11 B 1011 12 C 1100 13 D 1101 14 E 1110 15 F 1111: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-18
  • Computer Basics Component Function Bus Wires that connect the internal components to the CPU CD-ROM Drive Compact Disc Read-only memory Central Processing Unit (CPU) The computer “brain” where nearly all calculations are performed. Expansion Card A printed circuit board that can be inserted for additional functionality Expansion Slot An opening in the computer for expansion card Floppy disk drive A device for reading and writing to floppy disk Hard Disk Drive Used to store and retrieve data from nonvolatile storage media Microprocessor A silicon chip that contains a CPU Printed circuit Board A thin plate on which integrated circuit are placed Memory Internal Storage: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-19
  • Computer Basics Component Function Random Access Memory A temporary storage place for data while programs (RAM) are in use. If the computer loses power, all data in RAM that was not saved is lost. Read-only Memory (ROM) Prerecorded or “startup” memory System Unit The computer’s “main” box Socket A connector for expansion card Interface A device that connects to pieces of equipment (a mouse and computer, for example) Network Card A PCB that provides network access Parallel port An interface that communicates more than 1 bit of information at a time. Usually used to connect devices such as printer Serial Port An interface that communicate 1 bit at a time Universal Serial Bus (USB) An interface that allows other devices to be connected and disconnected without resetting the: Networking Fundamentals—Internetworking HVS system. Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-20
  • Reading…. Unit : 1 Topic: 1 “Introduction to Networking”: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-21
  • Homework to Next Class Decimal to Binary Binary to Decimal to Hexadecimal Decimal Hexadecimal to Decimal 1) 85 11001100 142 0B 2) 163 01110110 25 A1 3) 45 00101011 44 45 4) 98 10011001 192 59 5) 124 01001100 201 F0 6) 146 01100000 68 1C 7) 78 10011010 99 63 8) 110 10111100 115 79 9) 246 11111001 224 AA 10) 163 01110110 169 6D 11) 210 00010101 248 0F 12) 155 10101101 55 AC 13) 186 11101001 193 FB 14) 228 10110100 10 C5 15) 137 00111001 207 89: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-22
  • Revisión Investigación I 1) Qué es una red de datos? y cuáles son sus aplicaciones?. 2) Qué es una red de voz? Y cuáles son sus aplicaciones? 3) Tipos de redes existentes en la Industria. 4) Aplicaciones de una red de voz y datos en la industria actual. 5) Evolución y Nuevas tendencias de las redes en la actualidad?: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-23
  • ¿Que es una Red? Existen varias definiciones acerca de que es una red, algunas de las cuales son: •  Conjunto de operaciones centralizadas o distribuidas, con el fin de compartir recursos "hardware y software". •  Sistema de transmisión de datos que permite el intercambio de información entre ordenadores. •  Conjunto de nodos "computador" conectados entre sí. En español: Una red son dos ó más computadoras con sus periféricos asociados conectadas por un medio de comunicación.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-24
  • Ventajas de las Redes •  Trabajar lejos de la Oficina: Cuando se encuentra viajando o en la casa puede conectarse a la red de la oficina para intercambiar mensajes y archivos. •  Eliminar los Tenis: Se refiere a la manera física de trasladar la información de una computadora a otra para intercambiar información. Una red elimina esta necesidad. •  Compartir Información: Las redes permiten compartir los datos y programas. Por lo tanto puede intercambiar documentos, correo electrónico, video, sonido e imágenes. •  Compartir equipo: Las computadoras conectadas a una red pueden compartir equipo, tal como una impresora o un modem.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-25
  • Aplicaciones de Red Una red local proporciona la facilidad de compartir recursos entre sus usuarios. Esto es: •  Compartir Ficheros. Es la prestación principal de las redes locales. La aplicación básica consiste en utilizar ficheros de otros usuarios, sin necesidad de utilizar el disquete. •  Impresión en Red. Permiten que sus usuarios puedan acceder a impresoras de calidad y alto precio sin que suponga un desembolso prohibitivo. •  Aplicaciones en Red. El tipo de aplicaciones más importante son los programas de correo electrónico. •  Acceso a aplicaciones. •  Internet.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-26
  • Clasificación de las Redes Según la extensión geográfica: LAN (Local Area Network) MAN (Metropolitan Area Network) WAN (Wide Area Network) Según la topología: Red en anillo Red en árbol Red en malla Red en bus Red en estrella Según el medio de transmisión: Red cableada Red inalámbrica: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-27
  • Agenda •  Networking History •  OSI Reference Model •  How a LAN Is Built •  LAN Topologies •  LAN/WAN Devices: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-28
  • Networking History
  • Evolution of Internetworking History •  The first networks were time-sharing networks that used mainframes and attached terminals. Such environments were implemented using IBMs System Networks Architectures (SNA) and Digitals Digital Equipment Corporation (DECnet) network architecture. •  Local area Networks (LAN) evolved around the PC revolution. LANs allowed multiple users in a relatively small geographical area to exchange files and messages, and to access shared resources such as file servers. •  Wide area Networks (WAN) interconnect LANs across normal telephone lines (and other media), thereby interconnecting geographically dispersed users. •  Today, high-speed LANs and Switched internetworks are becoming widely used. These internetworks operate at very high speeds and support high-bandwidth applications such as voice and video conferencing.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-30
  • Early Networks • Samuel Morse • Alexander Graham Bell • Emile Baudot: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-31
  • Telephone Network Bell Telephone Analog Network: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-32
  • Telephone Network Bell Atlantic MCI AT&T Pacific Bell: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-33
  • 1960s–1970s Communications Digital Network Low-Speed Access Lines IBM Host Computer Systems Network Architecture (SNA) •  Application Programs •  Database •  Printing: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-34
  • Problem…: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-35
  • Analog and Digital Signals Digital Transmission— Analog Transmission— 1’s and 0’s Wires or wireless, On or Off Audio tones Computer-speak Info conveyed through signal amplitude, frequency, and phase 1 0 1 0 0 1 1 0 1 “1” bit “0” bit Start Stop Bit Bit: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-36
  • Solution—Modems •  Modem—Modulator/Demodulator Translates digital computer signals to analog signals which the telephone world can understand and vice versa: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-37
  • Solution—Modems •  Modem—Modulator/Demodulator Translates digital computer signals to analog signals which the telephone world can understand and vice versa POTS Mainframe Modem Modem Host POTS (Plain Old Telephone Service): Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-38
  • Another Solution—Multiplexing Multiplexer—Allows multiple signals to be carried across a single physical medium Broadband—Able to carry multiple signals simultaneously Mainframe Host Baseband—Carries only one signal at a time: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-39
  • Baseband versus Broadband Baseband— ! Local-Area Network! (LAN)! Broadband— ! Wide-Area Network ! (WAN)!: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-40
  • 1960s–1970s Communications Sunnyvale Branch Digital Digital POTS Headquarters, Mainframe Host San Francisco: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-41
  • 1960s–1970s Communications Sunnyvale Branch Dedicated Leased Lines Digital Digital Digital POTS Dialup Modem Connection Headquarters, Mainframe San Francisco Host Morgan Hill Branch: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-42
  • Birth of the Personal Computer •  Applications •  File storage •  Processing power •  Printing options •  Smart terminals: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-43
  • The Internet—1970s and 1980s •  ARPANET—Advanced Research Projects Agency Network, Dept. of Defense –  Developed in mid 1960s –  Funded research to universities and companies –  First packet-switched network built by BBN—Dec 1969 –  Many LANs connected to the ARPANET with TCP/IP –  Shut down in 1990 due to newer networks emerging •  NSFNET—National Science Foundation, late 1970s –  High-speed successor to ARPANET –  Six supercomputers: San Diego, Boulder, Champaign, Pittsburgh, Ithaca, and Princeton –  Supercomputers given a microcomputer which spoke TCP/IP –  Overloaded from the word “go”: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-44
  • 1990s—Global Internetworking •  1992—1 major backbone, 3,000 networks, 200K computers •  1995—Multiple backbones, hundreds of regional nets, tens of thousands of LAN’s, millions of hosts, tens of millions of users Doubling every year!: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-45
  • Introduction to Internetworking An internetwork is a collection of individual networks, connected by intermediate networking devices, that functions as a single large network. Internetworking refers to the industry, products, and procedures that meet the challenge of creating and administering internetworks.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-46
  • Internetworking Benefits Connectivity - The challenge of connectivity is to support communication between disparate technologies, such as different media types or speeds. Reliability - Reliable service is a must in any internetwork. Individual users and whole organizations are dependent on getting consistent, reliable access to network resources.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-47
  • Internetworking Benefits Management - Network management must provide centralized support and troubleshooting capabilities in an internetwork. Configuration, security, performance, and other issues must be adequately addressed in order for the internetwork to function smoothly. Flexibility - Flexibility is a necessity in the face of network expansion, new applications and services, and other such factors.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-48
  • Needs for Internetworking Three problems gave birth to the internetworking industry: •  Isolated LANs -- Electronic communication between different offices or departments was impossible. •  Duplication of resources -- The same hardware and software had to be supplied to each office or department. A separate, complete support staff had to be deployed at each site. •  Lack of network management -- There was no centralized way to manage and troubleshoot networks.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-49
  • OSI Reference Model
  • Agenda •  The Layered Model •  Layers 4–7: Transport, Session, Presentation, and Application Layers •  Layer 3: Network Layer •  Layers 1 & 2: Physical & Data Link Layers: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-51
  • The Layered Model
  • Open Systems Interconnection (OSI) Reference Model Overview The Open Systems Interconnection (OSI) reference model is a conceptual model composed of seven layers, each specifying particular network functions. The OSI model describes how information from a software application in one computer moves through a network medium to a software application in another computer. The model was developed by the International Organization for Standardization (ISO) in 1984. It is now considered the primary architectural model for intercomputer communications.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-53
  • Open Systems Interconnection (OSI) Reference Model Overview The Open Systems Interconnection (OSI) reference model is a standardized framework for network functions and schemes. It breaks otherwise-complex network interactions into simple elements, wich lets developers modularize design efforts. This methods allows many independent developers to work on separate network functions, which can be applied in a “plug and play” manner.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-54
  • Layered Communication Location A I like Message rabbits L: Dutch Information for the Ik hou Remote van Translator konijnen Fax #:--- Information L: Dutch for the Ik hou Remote van Secretary konijnen Source: Tanenbaum, 1996: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-55
  • Layered Communication Location A Location B I like J’aime Message rabbits les lapins L: Dutch Information L: Dutch for the Ik hou Ik hou Remote van van Translator konijnen konijnen Fax #:--- Fax #:--- Information L: Dutch L: Dutch for the Ik hou Ik hou Remote van van Secretary konijnen konijnen: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-56
  • Layered Communication Location A Location B Layers I like J’aime rabbits Message 3 les lapins L: Dutch Information L: Dutch Ik hou van for the remote 2 Ik hou van translator konijnen konijnen Fax #:--- Fax #:--- Information L: Dutch L: Dutch for the Ik hou Ik hou remote van konijnen secretary 1 van konijnen: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-57
  • Why a Layered Network Model? 7  Application •  Reduces complexity (one big problem to seven smaller 7  Presentation ones) 7  Session •  Standardizes interfaces •  Facilitates modular 7  Transport engineering 7  Network •  Assures interoperable technology 7  Data Link •  Accelerates evolution •  Simplifies teaching and 1 Physical learning: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-58
  • Why a Layered Network Model?: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-59
  • Devices Function at Layers 7  ApplicationNIC Card 7  Presentation 7  Session 7  Transport 7  Network 7  Data Link 1 Physical Hub: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-60
  • Host Layers } 7 Application 6 Presentation Host layers: Provide accurate data delivery 5 Session between computers 4 Transport 3  Network 2 Data Link 1 Physical: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-61
  • Media Layers } Application Presentation Host layers: Provide accurate data delivery Session between computers Transport (Upper layers) } Network Data Link Media layers: Control physical delivery of messages Physical over the network (Lower layers): Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-62
  • Layer Functions 7 Application Provides network services to application processes (such as electronic mail, file transfer, and terminal emulation): Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-63
  • Layer Functions 7 Application Network services to applications 6 Presentation Data representation •  Ensures data is readable by receiving system •  Format of data •  Data structures •  Negotiates data transfer syntax for application layer: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-64
  • Layer Functions 7 Application Network services to applications 6 Presentation Data representation 5 Session Inter-host communication ! •  Establishes, manages, and terminates sessions between applications: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-65
  • Layer Functions 7 Application Network services to applications 6 Presentation Data representation 5 Session Inter-host communication ! 4 Transport End-to-end connection reliability •  Concerned with data transport issues between hosts •  Data transport reliability •  Establishes, maintains, and terminates virtual circuits •  Fault detection and recovery •  Information flow control: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-66
  • Layer Functions 7 Application Network services to applications 6 Presentation Data representation 5 Session Inter-host communication 4 Transport End-to-end connection reliability 3 Network Addresses and best path •  Provides connectivity and path selection between two end systems •  Domain of routing: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-67
  • Layer Functions 7 Application Network services to applications 6 Presentation Data representation ! 5 Session Inter-host communication 4 Transport End-to-end connection reliability 3 Network Addresses and best path 2 Data Link Access to media •  Provides reliable transfer of data across media 1 Physical •  Physical addressing, network topology, error notification, flow control: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-68
  • Layer Functions 7 Application Network services to applications 6 Presentation Data representation ! 5 Session Inter-host communication 4 Transport End-to-end connection reliability 3 Network Addresses and best path 2 Data Link Access to media 1 Physical Binary transmission •  Wires, connectors, voltages, data rates: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-69
  • Layered Interchange Application Presentation PDU ! Upper Layer Data Session Transport Header Upper Layer Data Transport Segment Network Header Data Network Packet LLC Header Data FCS Data Link Frame MAC Header Data FCS 01011101010010000101000101 Physical Bit: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-70
  • Peer-to-Peer Communications Host A Host B 7 Application Application 6 Presentation Presentation 5 Session Session Segments 4 Transport Transport Packets 3 Network Network Frames 2 Data Link Data Link 1 Physical Bits Physical: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-71
  • OSI Communication Process: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-72
  • Data Encapsulation Host A Host B } { Application Application Presentation Data Presentation Session Session Transport Transport Network Network Data Link Data Link Physical Physical: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-73
  • Data Encapsulation Host A Host B } { Application Application Presentation Data Presentation Session Session Transport Transport Network Data Network Header Network Data Link Data Link Physical Physical: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-74
  • Data Encapsulation Host A Host B } { Application Application Presentation Data Presentation Session Session Transport Transport Network Data Header Network Network Frame Network Data Frame Data Link Data Link Header Header Trailer Physical Physical: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-75
  • Data Encapsulation Host A Host B } { Application Application Presentation Data Presentation Session Session Transport Transport Network Data Header Network Network Frame Network Data Frame Data Link Data Link Header Header Trailer Physical Physical 0101101010110001: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-76
  • Data Encapsulation: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-77
  • What is a Protocol? A protocol is a formal set of rules and conventions that govern how computers exchange information over a network medium. A protocol implements the functions of one or more layers of the OSI Model. There are a wide variety of communication protocols: •  LAN Protocols: Ethernet, Token Ring, FDDI •  WAN Protocols: Frame Relay, PPP •  Routing Protocols: RIP, EIGRP •  Routed Protocols: TCP/IP: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-78
  • Remaining Chapter Sequence Network Applications End-to-end Services Routing Data Transmission: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-79
  • ISO Hierarchy of Networks Nomenclatura OSI: End System: Pc’s Intermediate System: Routers Area: Local Network Autonomous System: Network Organization: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-80
  • Layers 4–7:Transport, Session, Presentation, and Application Layers
  • Application Layer COMPUTER APPLICATIONS NETWORK Word Processor APPLICATIONS INTERNETWORK APPLICATIONS Presentation Graphics Electronic Mail Spreadsheet File Transfer Electronic Data Interchange Database Remote Access World Wide Web Design/Manufacturing Client-Server Process E-Mail Gateways Project Planning Information Location Special-Interest Bulletin Boards Others Network Management Financial Transaction Services Others Internet Navigation Utilities Conferencing (Voice, Video, Data) Others•  Internetwork applications can extend beyond the enterprise (i.e., to suppliers, etc.) : Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-82
  • Presentation Layer Text • Graphics • Data • Visual images • ASCII PICT login: EBCDIC TIFF Encrypted JPEG • Sound GIF MIDI • Video MPEG QuickTime •  Provides code formatting and conversion for applications: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-83
  • Session Layer •  Network File System (NFS) •  Structured Query Language (SQL) •  Remote-Procedure Call (RPC) •  X Window System •  AppleTalk Session Protocol (ASP) •  DEC Session Control Protocol (SCP) Service Request Service Reply •  Coordinates applications as they interact on different hosts: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-84
  • Layers 4: Transport Layers© 1999, Cisco Systems, Inc. www.cisco.com
  • Transport Layer •  Segments upper-layer applications •  Establishes an end-to-end connection •  Sends segments from one end host to another •  Optionally, ensures data reliability: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-86
  • Transport Layer— Segments Upper-Layer Applications Application Electronic File Terminal Presentation Mail Transfer Session Session Transport Application Application Data Data Port Port Segments: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-87
  • Multiplexing Basics Multiplexing is a process in which multiple data channels are combined into a single data or physical channel at the source. Multiplexing can be implemented at any of the OSI layers. Demultiplexing is the process of separating multiplexed data channels at the destination.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-88
  • Transport Layer— Establishes Connection Sender Receiver Synchronize Negotiate Connection Synchronize Acknowledge Connection Established Data Transfer (Send Segments): Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-89
  • Connection-Oriented Sessions Connection-oriented service involves three phases:: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-90
  • Connectionless Network Service Connectionless network service does not predetermine the path from the source to the destination system, nor are packet sequencing, data throughput, and other network resources guaranteed. Each packet must be completely addressed because different paths through the network might be selected for different packets, based on a variety of influences. Each packet is transmitted independently by the source system and is handled independently by intermediate network devices.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-91
  • Transport Layer— Sends Segments with Flow Control Transmit Sender Receiver Buffer Full Not Ready Stop Process Segments Go Ready Buffer OK Resume Transmission: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-92
  • Buffering Buffering is used by network devices to temporarily store bursts of excess data in memory until they can be processed.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-93
  • Source Quench Messages Source quench messages are used by receiving devices to help prevent their buffers from overflowing.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-94
  • Transport Layer— Reliability with Windowing • Window Size = 1 Send 1 Receive 1 Ack 2 Sender Send 2 Receive 2 Receiver Ack 3 • Window Size = 3 Send 1 Receive 1 Send 2 Receive 2 Sender Send 3 Receive 3 Receiver Ack 4 Send 4: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-95
  • Reliability with Windowing Windowing is a flow-control scheme in which the source device requires an acknowledgement from the destination after a certain number of packets have been transmitted.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-96
  • Transport Layer— An Acknowledgement Technique Sender Receiver 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Send 1 Send 2 Send 3 Ack 4 Send 4 Send 5 Send 6 Ack 5 Send 5 Ack 7: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-97
  • Error Checking Basics Error-checking schemes determine whether transmitted data has become corrupted or otherwise damaged in traveling from source to destination. Error checking is implemented at a number of the OSI layers. One common error-checking scheme is the cyclic redundancy check (CRC).: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-98
  • Transport to Network Layer End-to-End Segments Routed Packets: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-99
  • Summary •  The ISO/OSI reference model describes network applications •  Presentation layer formats and converts network application data to represent text, graphics, images, video, and audio •  Session-layer functions coordinate communication interactions between applications. •  Reliable transport-layer functions include: –  Multiplexing –  Flow control –  Reliability with Windowing: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-100
  • Layer 3: Network Layer© 1999, Cisco Systems, Inc. www.cisco.com
  • Network layer The network layer provides routing and related functions that allow multiple data links to be combined into an internetwork. This is accomplished by the logical addressing (as opposed to the physical addressing) of devices. The network layer supports both connection-oriented and connectionless service from higher-layer protocols.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-102
  • What is Routing?© 1999, Cisco Systems, Inc. www.cisco.com
  • What Is Routing? •  Routing is: –  Finding a path between a source and destination (path determination) –  Moving information across an internetwork from a source to a destination (switching*) –  Very complex in large networks because of the many potential intermediate nodes •  A router is: –  A network layer device that forwards packets from one network to another and determines the optimal path for forwarding network traffic * The term “switching”, when used to describe a router’s function, is different from a switch (the network device).: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-104
  • Routers—Layer 3 Remote Routing Table Location 192.168.3.0 Frame Relay 192.168.1.0 Ethernet 192.168.2.0 FDDI Network 192.168.3.0 Frame Relay Main Site Network 192.168.2.0 FDDI Network 192.168.1.0 Ethernet: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-105
  • Where are Routers Used? • LAN-to-LAN connectivity • LAN-to-WAN connectivity • Remote access: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-106
  • Path Determination 5 2 8 9 4 Which Path? 6 10 11 1 3 7 •  Routers find the best path through the network –  Routing tables contain route information –  Network addresses represent the path of media connections to a destination: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-107
  • Path Determination •  Routers find the best path through the network –  Routing tables contain route information –  Network addresses represent the path of media connections to a destination: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-108
  • Network Layer: Communicate Path 5 2 9 6 8 4 10 11 1 3 7 •  Addresses represent the path of media connections •  Routing helps contain broadcasts: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-109
  • Routing Tables •  Routing algorithms –  Initialize and maintain To Reach Send routing tables to help with path determination Network: To: •  Route information types 27 Node A –  Destination/next-hop associations 57 Node B 17 Node C –  Path desirability 24 Node B –  Vary depending on routing algorithm 11 Node B 72 Node A •  Message = Routing table maintenance communications –  Routing update messages –  Link-state advertisement: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-110
  • Routing Algorithm Goals •  Optimality –  Selecting the best route based on metrics and metric weightings used in the calculation •  Simplicity and low overhead –  Efficient routing algorithm functionality with a minimum of software and utilization overhead •  Robustness and stability –  Correct performance in the face of unusual or unforeseen circumstances (e.g., high load) •  Rapid convergence –  Fast agreement, by all routers, on optimal routes •  Flexibility –  Quick and accurate adaptation to changes in router availability, bandwidth, queue size, etc.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-111
  • Routing Metrics •  Path length –  Total hop count or sum of cost per network link •  Reliability –  Dependability (bit error rate) of each network link •  Delay –  Useful because it depends on bandwidth, queues, network congestion, and physical distance •  Communication cost –  Operating expenses of links (private versus public) •  Bandwidth and load: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-112
  • Network Addressing© 1999, Cisco Systems, Inc. www.cisco.com
  • Hierarchical versus Flat Address Space: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-114
  • Network and Node Addresses Network Node 2 1 1 2.1 2 1.2 3 1.1 3.1 2 1 1.3 1 3 3 1 •  Network address—Path part used by the router •  Node address—Specific port or device on the network: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-115
  • Addressing Examples: Protocol Addressing Variations Network Node/Host Protocol Address Address General 1. 4 TCP/IP 10. 8.2.48 Novell IPX 1aceb0b 0000.0c00.6e25 AppleTalk 10. 1. X.25 DNIC NTN NTN: National Terminal Number: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-116
  • Address Assignment Addresses are assigned to devices in one of three ways: • Static: Static addresses are assigned by a network administrator. Static address does not change until the network administrator manually changes it. • Dynamic: Dynamic addresses are obtained by devices when they attach to a network. • Server: Addresses assigned by a server are given to devices as they connect to the network. Server assigned addresses are recycled for reuse as devices disconnect. A device is therefore likely to have a different address each time it connects to the network.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-117
  • Subnetwork Addressing INTERNET 131.108.0.0 131.108.1.0 Subdividing address space into smaller blocks 131.108.2.0 131.108.3.0 –  Helps organize network 131.108.5.0 –  Security (keeps HR HR 131.108.4.0 separately addressable) 131.108.6.0 131.108. 8.0 –  Scalability—Keeps traffic to appropriate segments –  Allows single, summarized Manufacturing routing entry (131.108.0.0) to 131.108.9.0 131.108.7.0 be advertised to external networks R&D –  Specific route entries 131.108.10.0 (131.108.8.0) required only for routers in the subnetted block: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-118
  • Network Layer: Path Switching X Y C C A A •  Each router provides its services to support upper layer functions: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-119
  • Routers: Path Switching (Layer 3): Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-120
  • Network Layer Protocol Operations X Y C C A A B B Host X Host Y Application Application Presentation Presentation Session Router A Router B Router C Session Transport Transport Network Network Network Network Network Data Link Data Link Data Link Data Link Data Link Physical Physical Physical Physical Physical •  Each router provides its services to support upper layer functions: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-121
  • Multiprotocol Routing Routing Tables IPX 3a.0800.5678.12ab Novell Apple IP 15.16.50.3IPX 4b.0800.0121.ab13 DEC IP Token Ring AppleTalk 100.110 VAX DECnet 5.8 Token Ring VAX IP 15.16.42.8 DECnet 10.1 AppleTalk 200.167 IP 15.17.132.6 •  Routers pass traffic from all routed protocols over the internetwork: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-122
  • Routed Versus Routing Protocol• Routed protocol used between routers to direct user traffic Examples: IP, IPX, AppleTalk, DECnet Network Destination Exit Port Protocol Network to Use Protocol Name 1.0 1.1 2.0 2.1 3.0 3.1: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-123
  • Routed Versus Routing Protocol• Routed protocol used between routers to direct user traffic Examples: IP, IPX, AppleTalk, DECnet• Routing protocol used only between routers to maintain routing tables Examples: RIP, IGRP, OSPF: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-124
  • Static Versus Dynamic Routes Static Route Uses a protocol route that a network administrator enters into the router Dynamic Route Uses a route that a network protocol adjusts automatically for topology or traffic changes: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-125
  • Static Routing •  Manual table updates by a network administrator •  Benefits –  Reflects administrator’s special topology knowledge A –  Private—Not conveyed to other routers in updates –  Avoids the overhead of dynamic routing •  Stub network Only a single network –  When a node is accessible by Bconnection with no need only one path, a static route is for routing updates sufficient “Stub” Network –  Point-to-point or circuit-switched connection : Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-126
  • Summary • Routers move data across networks from a source to a destination • Routers determine the optimal path for forwarding network traffic • Routing protocols communicate reachability information between routers: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-127
  • Layers 1 & 2:Physical & Data Link Layers© 1999, Cisco Systems, Inc. www.cisco.com
  • Data Link layer The data link layer provides reliable transit of data across a physical network link.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-129
  • Data Link Sublayer The Logical Link Control (LLC) sublayer of the data link layer manages communications between devices over a single link of a network. Logical Link Control (LLC) is the upper sublayer of the OSI data link layer. 1.  The LLC sublayer is primarily concerned with: Multiplexing protocols transmitted over the MAC layer (when transmitting) and demultiplexing them (when receiving). that make it possible for several network protocols (IP, IPX, Appletalk) to coexist within a multipoint network and to be transported over the same network media 2.  Providing flow control and detection and retransmission of dropped packets, if requested. LLC is defined in the IEEE 802.2 specification.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-130
  • Data Link Sublayer The Media Access Control (MAC) sublayer of the data link layer manages protocol access to the physical network medium.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-131
  • Physical layer The physical layer defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between communicating network systems. Different data link layer specifications define different network and protocol characteristics, including the following: •  Physical addressing •  Network topology •  Error notification •  Sequencing of frames •  Flow control: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-132
  • Physical & Data link Layer The physical and data link layers are usually implemented together in hardware/software combination solutions. Examples include: hubs, switches, and network adapters, and their applicable software drivers, as well as the media or cables used to connect network nodes. The IEEE (Institute of Electrical and Electronics Engineers) created several standards under the 802 series.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-133
  • Remaining Chapter Sequence OSI MODEL Application User Interface Telnet, HTTP Presentation Encryption and other processing ASCII /EBCDIC Session Manages multiple Applications Operating System Transport Provides reliable or best-effor delivery and TCP, UDP, SPX some error correction Network Provides logical addressing used by routers IP, IPX and the network hierarchy. Data link Creates frames from bits of data 802.3 LAN Uses MAC Address to access endpoints 802.2 Provides error detection but not correction HDLC, WAN Frame relay Physical Specifies voltage, wire speed, and cable pin EIA/TIA outs V.35: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-134
  • En español…..: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-135
  • Exercises
  • Internetworking Addressing Internetwork addresses identify devices uniquely or as a member of a group. Addressing schemes vary depending on the protocol family and the layer of the OSI model. Three types of internetwork addresses are commonly used: • Data link layer addresses • Media Access Control (MAC) addresses • Network layer addresses: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-137
  • Physical and Logical Addressing 0000.0c12.3456: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-138
  • Data Link layer Addresses A data link layer address uniquely identifies each physical network connection of a network device. Data link addresses are sometimes referred to as physical or hardware addresses. End systems typically have only one physical network connection, and thus have only one data link address. Routers and other internetworking devices typically have multiple physical network connections.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-139
  • Data Link layer Addresses: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-140
  • Network layer Addresses A network layer address identifies an entity at the network layer of the OSI reference model.They are sometimes called virtual or logical addresses. The relationship of a network address with a device is logical and unfixed. It is typically based either on physical network characteristics (the device is on a particular network segment) or on groupings that have no physical basis: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-141
  • MAC Address MAC addresses are 48 bits in length and are expressed as 12 hexadecimal digits: •The first 6 hexadecimal digits are the manufacturer identification (or vendor code), called the Organizational Unique Identifier (OUI). These 6 digits are administered by the IEEE. •The last 6 hexadecimal digits are the interface serial number or another value administered by the specific vendor.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-142
  • MAC Address 24 bits 24 bits Vendor Code Serial Number 0000.0c12. 3456 ROM RAM •  MAC address is burned into ROM on a network interface card: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-143
  • Address Resolution Address resolution is the process of mapping network addresses to Media Access Control (MAC) addresses. This process is accomplished using the Address Resolution Protocol (ARP). When a network address is successfully associated with a MAC address, the network device stores the information in the ARP cache.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-144
  • Address Resolution on a single LAN: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-145
  • Address resolution Across LAN: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-146
  • Routers: Path Switching (Layer 3): Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-147
  • Hello Protocol The Hello protocol is a network layer protocol that allows network devices to identify one another and indicate that they are still functional.: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-148
  • Summary •  OSI reference model describes building blocks of functions for program-to- program communications between similar or dissimilar hosts •  Layers 4–7 (host layers) provide accurate data delivery between computers •  Layers 1–3 (media layers) control physical delivery of data over the network: Networking Fundamentals—Internetworking HVS Universidad Autónoma de Yucatán . I.S.C Henry Ventura Sabido 1-149
  • Exercises
  • : Networking Fundamentals—Internetworking HVSPresentation_ID © 1999, Cisco Systems, Inc. Universidad Autónoma de Yucatán www.cisco.com . I.S.C Henry Ventura Sabido 1-151 151