Transcript Chapter 1 x
Chapter 1 1 Introduction to Networking Fundamental Network Characteristics Type and Sizes of Networks Network Performance issues and Concepts Network Standard and Standard Organizations 2 Define the elements of communication – 3 common elements of communication • Message source • The channel • Message destination Define a network – Data or information networks capable of carrying many different types of communications A network is a set of hardware devices connected together, either physically or logically to allow them to exchange information. 4 Connectivity and Communication Data, Hardware Sharing Internet Access Data Security and Management Performance Enhancement and Balancing Entertainment 5 Network Hardware, Software and Setup Costs Hardware and Software Management and Administration Costs Undesirable Sharing Illegal or Undesirable Behavior Data Security Concerns 6 Define the components of a network – Network components • Hardware • Software End Devices and their Role in the Network – End devices form interface with human network & communications network – Role of end devices: • Client • Server • Both client and server Identify the role of an intermediary device in a data network and be able to contrast that role with the role of an end device – Role of an intermediary device • Provides connectivity and ensures data flows across network Define network media and criteria for making a network media choice – Network media – this is the channel over which a message travels Networking Layers ◦ Networking technologies are most often compartmentalized in this manner by dividing their functions into layers, each of which contains hardware and/or software elements. Networking Models Networking Architectures ◦ Open Systems Interconnection (OSI) ◦ An architecture is essentially a set of rules that describes the function of some portion of the hardware and software that constitute a stack of layers. 11 A networking protocol defines a set of rules, algorithms, messages and other mechanisms that enable software and hardware in networked devices to communicate effectively. A protocol usually describes a means for communication between corresponding entities at the same OSI Reference Model layer in two or more devices. 12 13 14 A connection-oriented protocol is one where a logical connection is first established between devices prior to data being sent. 15 In a connectionless protocol, data is just sent without a connection being created. 16 TCP/IP, it has two main protocols that operate at the transport layer of the OSI Reference Model. One is the Transmission Control Protocol (TCP), which is connectionoriented; the other, the User Datagram Protocol (UDP), is connectionless. 17 Common Names For Messages ◦ Packet/Datagram ◦ Frame/Cell ◦ Protocol Data Unit (PDU) and Service Data Unit (SDU) 18 Fundamental Message Elements ◦ Header ◦ Data ◦ Footer 19 Message Transmission Methods ◦ Unicast Messages ◦ Broadcast Messages ◦ Multicast Messages 20 21 Unicast Addressing Broadcast Addressing Multicast Addressing 22 Local Area Networks (LANs) Wireless Local Area Networks (Wireless LANs or WLANs): Wide Area Networks (WANs) Campus Area Networks (CANs): Metropolitan Area Networks (MANs): ◦ WMANs; IEEE 802.16 is an example of a WMAN standard Personal Area Networks (PANs) 23 Define Local Area Networks (LANs) – A network serving a home, building or campus is considered a Local Area Network (LAN) Define Wide Area Networks (WANs) – LANs separated by geographic distance are connected by a network known as a Wide Area Network (WAN) Define the Internet – The internet is defined as a global mesh of interconnected networks Network Sub-network (Subnet) Segment (Network Segment) ◦ Collision Domain ◦ Broadcast Domain Internetwork (or Internet) 27 Balancing Network Performance with Key Non-Performance Characteristics ◦ ◦ ◦ ◦ ◦ ◦ ◦ Design and Implementation Cost: Quality Standardization Reliability Expandability and Upgradability Ease of Administration and Maintenance Premises and Utility issues 28 Speed Bandwidth Throughput Latency 29 Normal Network Overhead External Performance Limiters Network Configuration Problems The Effect of Asymmetry 30 Simplex Operation Half-Duplex Operation Full-Duplex Operation 31 Bandwidth Reservation Latency Management: Traffic Prioritization Traffic Shaping Network Congestion Avoidance 32 Proprietary Standards Open Standards De Facto Standards 33 International Organization for Standardization (ISO): American National Standards Institute (ANSI): Information Technology Industry Council (ITIC): National Committee for Information Technology (NCITS): Institute of Electrical and Electronics Engineers (IEEE): Electronic Industries Alliance (EIA): Telecommunications Industry Association (TIA): International Telecommunication Union Telecommunication Standardization Sector (ITU-T): European Telecommunications Standards Institute (ETSI): 34 Internet Society (ISOC): ◦ Internet Architecture Board (IAB): Internet Engineering Task Force (IETF): Internet Engineering Steering Group (IESG): Internet Research Task Force (IRTF): Internet Research Steering Group (IRSG): 35 Internet Assigned Numbers Authority (IANA) ◦ Asia Pacific Network Information Centre (APNIC): ◦ American Registry for Internet Numbers (ARIN): ◦ Latin American and Caribbean Internet Addresses Registry (LACNIC): ◦ Réseaux IP Européens Network Coordination Center (RIPE NCC): Internet Corporation for Assigned Names and Numbers (ICANN) 36 RFC Categories ◦ ◦ ◦ ◦ Proposed Standard / Draft Standard / Standard: Best Current Practice Informational Experimental http://www.rfc-editor.org/rfc-index.html 37 38