1 / 32

Communicating over the Network

Communicating over the Network. Network Fundamentals – Lecture 2 (CCNA1 – Chapter 2). Objectives. Describe the structure 結構 of a network , including the devices and media that are necessary for successful communications. Explain the function 功能 of protocols 協定in network communications.

martin-blanchard
Download Presentation

Communicating over the Network

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Communicating over the Network Network Fundamentals – Lecture 2 (CCNA1 – Chapter 2)

  2. Objectives • Describe the structure 結構of a network, including the devices and media that are necessary for successful communications. • Explain the function 功能of protocols協定in network communications. • Explain the advantages 好處 of using a layered model to describe network functionality. • Describe the role 角色of each layer in two recognized network models: The TCP/IP model and the OSI model. • Describe the importance of addressing 編址 and naming schemes方案 in network communications.

  3. 信息 訊號 傳送媒介 加密 傳送器 接受器 解碼器 來源 目的地 渠道 Network Structure • What is a network? • Data or information networks capable of carrying many different types of communications • 3 common elements of communication • message信息 source 來源 , the channel/media 媒介 , message destination 目的地

  4. How messages are communicated • Data is sent across a network in small “chunks” called segments (段落) 插入 Segmentation: Breaking communication into pieces Multiplexing: Interleaving the pieces as they transverse the media

  5. Network components 成分 • Hardware • device; media • Software/service

  6. Basic Network Components • Network devices / Intermediary中間的 devices • provide connectivity連接 and ensure data flows in the network • e.g. Router 路由器, Switch 交換器, Hub 中轉站, Wireless device, etc. • End devices • provide services directly to end users • is the interface between human and network • e.g. PC, server, networked printers, etc. • Network media (medium) • Network cable, wireless media

  7. Role (作用) of end devices 流動 來自 通過 • Act as client or server or both 到達 選擇路線

  8. Basic Network Components • Network media • Channel over which a message travels • Factors 要素 to choose the media • Speed, Cost, • Mobility流動性 • Distance • Environment • Data Amount Network Media Copper -electrical signal Fiber Optics -light pulse Wireless -infra-red, radio frequency

  9. Software/Services Services and processes are the communication programs, called software, that run on the networked devices. A network service provides information in response to a request.

  10. Network Types • Local Area Networks (LANs) • - A network serving a home, building or campus is considered a Local Area Network (LAN)

  11. Network Types • Wide Area Networks (WANs) • - LANs separated by geographic distance are connected by a network known as a Wide Area Network (WAN)

  12. Network Types • Internet is defined as • A global mesh of interconnected networks

  13. Network Symbols

  14. Protocols (協定) • The importance of protocols and how they are used to facilitate communication over data networks • A protocol is a set of predetermined (預先決定)rules (規則) to govern communications

  15. Protocols Message format Network protocols • are used • to allow devices to • communicate • successfully Sharing method Error handling Set up and Termination

  16. Technology independent Protocols • Different types of network devices can communicate using the same sets of protocols. • This is because protocols specify (詳細指明) network functionality (功能), not the technology (技術) of devices

  17. Protocols in Network Communication Protocol suites and industry standards A protocol suite 協議系列 is A group of inter-related protocols that are necessary to perform a communication function. They are implemented in software and hardware that is loaded on each host and network device. For example: TCP/IP suite A standard 標準 is A process or protocol that has been endorsed 認可by the networking industry and ratified 批准 by a standards organization. For example:The Institute of Electrical and Electronics Engineers (IEEE); Internet Engineering Task Force (IETF)

  18. Example of protocol suites • The interaction between a Web server and a Web browser as an example to explain the protocol suites

  19. Layered Network Model • Benefits of using a layered model • include • assists in protocol design • fosters competition • changes in one layer do not affect other layers • provides a common language

  20. Networking Models Two basic types of networking models: • Protocol model • It provides a model that closely matches the structure of a particular protocol suite. • For example: • TCP/IP model is a protocol model because it describes the functions that occur at each layer of protocols within the TCP/IP suite. • Reference model參考模型 • It provides a common reference for maintaining 保持 consistency 一致 within all types of network protocols and services. I • ts primary purpose is to aid in clearer understanding of the functions and process involved. • For example: • Open Systems Interconnection (OSI) model

  21. TCP/IP Model • Created in the early 1970s and is referred to as the Internet model • Open Standard 描述 譯成密碼 控制 對話 不同的 決定 路線

  22. Communication Process

  23. Protocol Data Unit • Protocol data units 協議數據單元 (PDU) and encapsulation 封裝 Encapsulation process ProtocolData Unit

  24. Process of sending and receiving messages

  25. OSI Model • It provides a framework架構 on which to build a suite of open systems protocols. • Unfortunately, the speed at which the TCP/IP based Internet was adopted, and the rate at which it expanded, caused the OSI Protocol Suite development and acceptance to lag behind.

  26. Layers with TCP/IP and OSI Model • Compare OSI and TCP/IP model 應用層 應用層 展示層 會談層 傳輸層 傳輸層 網際網路層 網路層 資料鏈結層 網絡接達層 實體層

  27. Addressing and Naming Schemes • Encapsulation 封裝 headers表頭 are used to manage communication in data networks • Using the OSI model as a guide, we can see the different addresses and identifiers 識別號 that are necessary at each layer Port number IP Address MAC Address TCP Segment IP Packet Ethernet Frame

  28. Addressing and Naming Schemes • Destination and source physical addresses is concerned with the delivery of messages on a single local network. • For example: In an Ethernet LAN, this address is called the Media Access Control (MAC) address.

  29. Addressing and Naming Schemes • Destination and source logical network addresses are used to manage communication in different data networks. • For example: IP address

  30. IP Address and MAC address • Use “ipconfig /all” to show the IP address and MAC address (Physical Address) of a PC

  31. Addressing and Naming Schemes • Destination and Source port numbers are used to identify the source and destination processes for data communication.

  32. Key Concepts of Chapter 2 Data Network Structures and Types End Devices, Intermediary Devices, Media, Software/Service LAN, WAN, Internet, Intranet Message Transfer using Layers Benefits, Protocol Model and Reference Model (TCP/IP and OSI) Addressing Schemes Encapsulation and PDUs Data, Segments, Packets, Frames and Bits

More Related