Presentation on theme: "Communicating over the Network"— Presentation transcript:
1Communicating over the Network Network Fundamentals – Chapter 2Sandra Coleman, CCNA, CCAI
2ObjectivesDescribe the structure of a network, including the devices and media that are necessary for successful communications.Explain the function of protocols in network communications.Explain the advantages of using a layered model to describe network functionality.Describe the role of each layer in two recognized network models: The TCP/IP model and the OSI model.Describe the importance of addressing and naming schemes in network communications.
3Network Structure Three elements of communication Message source The channelMessage destinationData or information networks capable of carrying many different types of communications
4How are messages communicated? Data is sent across a network in small “chunks” called segments – known as segmentationMultiplexing – describes the process of interleaving multiple digital data streams into ONE signal (see example in online curriculum 2.1.2)It increases the reliability of network communicationsDisadvantage is the amount of encapsulation that must occur with every segment, especially for large amounts of data!
5Network Components Hardware (includes devices and media) Software (services and processes)
6End DevicesEnd devices form interface with human network & communications networkOriginate data flow!Examples: computers, printers, VoIP Phones, cameras, cell phones, etc.Commonly referred to as hosts (source or destination of a message)Each host has an address that will identify it on the networkRole of end devices:Client (software installed so they can request & display info from the server)Server (provide information and services to other hosts)Both client and server
7Intermediary Devices Role of an intermediary device Examples: Hubs, switches, access points, routers, modems, firewalls, etc.Provides connectivity and manages data flows across networkWorks behind the scenesDetermines the path data will travel to get from source to destinationKnows all the paths that existInforms other like devices about errors or communication failuresRetimes & retransmits signals as necessary
8Network Media this is the channel over which a message travels Encoding is different for each type, i.e. electrical impulses, light pulses, wave patterns
9Network Types Local Area Networks (LANs) A network serving a home, building or campus is considered a Local Area Network (LAN)Single geographic area, usually a common organizationAdministered by a single organizationProvides network services to a common organization
10Network Types Wide Area Networks (WANs) LANs separated by geographic distance are connected by a network known as a Wide Area Network (WAN)Be able to identify a LAN and a WAN given a similar diagram
11Network Types Define the Internet The internet is defined as a global mesh of interconnected networks
13Function of Protocol in Network Communication A protocol is a set of predetermined rulesImplemented in software that is loaded on each host and network deviceView them as a stack – from low to high in a hierarchyOutline the functions necessary to communicate between layers
14Network ProtocolsNetwork protocols are used to allow devices to communicate successfullyProtocols agree on structure of message (specific to PDU’s)Protocols agree on the process of sharing, error handling, and termination procedures – all functions necessary for communicationRequire layer dependent encapsulations
15Protocols and Industry standards A standard is a process or protocol that has been endorsed by the networking industry and ratified by a standards organizationEnsures all protocols (open or proprietary) will work togetherIEEE (Institute of Electrical and Electronic Engineers)IETF (Internet Engineering Task Force)
16Function of Protocol in Network Communication Examples of Protocols
17Function of Protocol in Network Communication Technology independent ProtocolsMany diverse types of devices can communicate using the same sets of protocolsThis is because protocols specify network functionality, not the underlying technology to support this functionality
18Layers with TCP/IP and OSI Model Benefits of using a layered modelAssists in protocol designFosters competition (different vendors can work together)Changes in one layer do not affect other layersProvides a common language
19Layers with TCP/IP and OSI Model AwayPizzaSausageThrowNotDoProgrammersKnow the layers in order!
20Layers with TCP/IP and OSI Model TCP/IP Model – created in early 1970s – KNOW what each layer is responsible for!Open Standard
21Layers with TCP/IP and OSI Model Protocol data units (PDU) and encapsulationPDUs are SPECIFIC to each layer!Know PDUs at EACH layer!
22Key functions of encapsulation Ensure that data pieces get from sending to receiving deviceAbility to re-assemble the data packets correctlyAbility to identify data packets that belong together with the same communication package
23Comparing TCP/IP and OSI Model Know these layers and how they compare between the two models
24Addressing and Naming Schemes Explain how labels in encapsulation headers are used to manage communication in data networks
25Addressing and Naming Schemes Describe examples of Ethernet MAC Addresses, IP Addresses, and TCP/UDP Port numbers
26Addressing and Naming Schemes Think about a computer that has only one network interface on it. All the data streams created by the applications that are running on the PC enter and leave through that one interface, yet instant messages do not popup in the middle of word processor document or showing up in a game.This is because the individual processes running on the source and destination hosts communicate with each other. Each application or service is represented at Layer 4 by a port number.
27Things to do NOW! Demonstrate tracert Demonstrate packet tracer…how to set up a networkMap them a drive to Public…
28Ch. 2 is Finished! Labs & Skills Integration Lab 2-1 (Do this on PT , pg. 48 in lab book- I have the files from the CD loaded on public)Ch. 2 Test will be on Tuesday Sept. 5 or Wed. Sept 6, 2012Online Test – Must be taken by midnight on Sunday September 2, I will NOT turn it on again!Homework – due on test day!Study Guidep. 34 – Matching (table 2-1 & 2-2)p – Matching (table 2-3 & 2-4)p – Matching (table 2-5 & 2-6)Packet Tracer Activities in the textbook(pg. 44)(pg. 54)