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Chapter 5. Data Communication And Internet Technology. Purpose. Understand the fundamental networking concepts. Agenda. Network Concepts Communication Protocol TCP/IP-OSI Architecture Network Types LAN WAN Public Switched Data Network Virtual Private Network Network Comparison
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Chapter 5 Data Communication And Internet Technology
Purpose • Understand the fundamental networking concepts
Agenda • Network Concepts • Communication Protocol • TCP/IP-OSI Architecture • Network Types • LAN • WAN • Public Switched Data Network • Virtual Private Network • Network Comparison • Internet • Domain Name System • IP Addressing Schemes • Security • Discussion and Case Study
Network Concepts • A collection of computers that communicate with one another over transmission lines • Types • Local area networks (LANs): connects computers in a single geographic location • Wide area networks (WANs): connects computers at different geographic sites • Internet: a network of networks
Communication Protocol • Protocol: a standard means for coordinating an activity between two or more entities • Communications protocol: a means for coordinating activity between two or more communicating computers • The communication protocol is broken into levels of layers • Two machines must agree upon and follow the protocol for exchanging the message
TCP/IP-ISO Architecture - I • International Organization for Standardization (ISO): Reference Model for Open Systems Interconnection (OSI) • Internet Engineering Task Force (IETF): Transmission Control Program/Internet Protocol (TCP/IP) • TCP/IP-ISO architecture: five layers
TCP/IP-ISO Architecture - II • Layer 5 (Application): communication rules between two applications • Simple Mail Transfer Protocol (SMTP) for email • Hypertext Transfer Protocol (HTTP) for processing Web page (sites and users) • File Transfer Protocol (FTP) for copying file between computers
TCP/IP-ISO Architecture - III • Layer 4 (Transport): communication rules between two host computers • Transmission Control Program (TCP) • Sending functions: break data into segments, add To and From address, and • Receiving functions: provide reliability by sending acknowledgement, and translate the format, assemble segments into data
TCP/IP-ISO Architecture - IV • Layer 3 (Internet): communication rules of routing packets across the Internet • Internet Protocol (IP) • Functions: package each segment into a packet, place IP data in in the packet, add To/From data
TCP/IP-ISO Architecture - V • Layer 2 (Data Link): communication rule for transmitting data within a single network • Functions: package packets into frames • Layer 1 (Physical): communication rule between adjacent device connected by a transmission medium
Terminology • Architecture: an arrangement of protocol layers with their associated tasks • Protocol: set of rule to accomplish the tasks • Program: software implementing the protocol • Web: sub set of Internet with users and sites to process protocol • Internet: communication structure • Browser: a program implementing the HTTP of the TCP/IP-OSI architecture (Netscape and Microsoft Internet Explorer)
Network Types • LAN: local area network • WAN: wide area network
LAN - I • A group of computers connected together on a single company site and operated by the company • Equipments • Network interface card (NIC) or onboard NIC: an unique identifier named MAC (media access control) address • Unshielded twisted pair (UTP) cable with RJ-45 connecter • Optical fiber cable with ST and SC connectors
LAN - II • IEEE (Institute for Electrical and Electronics Engineers) • Protocol: IEEE 802.3 or Ethernet • Hardware characteristics (which wire carries which signals) • Package and process message over LAN • Operate on Layer 1 and 2 • 10/100/1000 Ethernet (Mbps) • Bits for communications speeds and bytes for memory sizes
LAN - III • Wireless LAN • Wireless NIC (WNIC) • IEEE 802.11g protocol to connect to an access point (AP) and IEEE 802.3
WAN • Connects computers located at physically separated sites • Internet service provider (ISP) • Provide customer a legitimate Internet address. • Serve as the gateway to the Internet • Communicate between sending computer and Internet • Connecting computer and ISP • Telephone line • DSL (digital subscriber line) • Cable TV line
WAN - Equipment • Modem • Convert data between digital and analog • Narrowband with speed less than 56 kbps and Broadband with speed over 256 kbps • Modem types • Dial-Up modem • Narrowband • Point-to-Point Protocol (PPP) • DSL modem • Permanent connection and one more line for telephone conversation • Asymmetric digital subscriber line (ADSL) for home and small business with slow upload speed with 256 kbps and faster download speed ranging from 256 to 768 kbps • Symmetric digital subscriber line (SDSL) for advanced users and larger business with 1.544 Mbps performance level guarantees • Cable modem • Permanent connection and one more line for TV • 10 Mbps download speed and 256 kbps upload speed
WAN - Equipment • Access devices • Switch (Layer 2) • Router (Layer 3) • Lease lines from telecommunication company • T1 line with 1.544 Mbps speed • T3 line with 44.763 Mbps speed • Optical fiber cable-768 with 40 Gbps • Point-to-Point Protocol (PPP)
WAN – Public Switched Data Network • Public switched data network (PSDN) • Developed and maintained by a vendor for selling time to other company • Shown as a cloud in the map or diagram • User must have a leased line connecting to PSDN as point of presence (POP) • PSDN types • Frame Relay with 56 kbps to 40 Mbps: slower and cost less but simple and easy to support • Asynchronous transfer mode (ATM) with 1 to 156 Mbps: faster and cost more but transmitting data and voice • Ethernet with 10 to 40 Gpbs
WAN – Virtual Private Network • Virtual private network (VPN): a private internet as a private point-to-point connection • Tunnel: a virtual, private pathway over a public or shared network from the VPN client to the VPN server • Encrypted message • Remote access
Network Comparison • Setup costs • Equipment: lines, switches, routers, and access devices • Labor • Operational costs • Lease fees for line and equipment • ISP charges • Training • Maintenance: problem diagnosis, repair, and updating • Performance • Speed: line and equipment • Latency: transmission delay due to congestion • Availability: service outages • Loss rate: transmission problem • Transparency • Performance guarantee: availability, error rate, speed, etc. • Growth potential • Contract commitment period • Management time • Financial risk • Technical risk
Internet • Network address • Physical or MAC address in Layer 2 program: permanent and unique • Logical or IP address in Layers 3, 4, and 5: not permanent, such as 192.168.2.28 • Public IP address used on the Internet to major institutions in blocks assigned by Internet Corporation for Assigned Names and Numbers (ICANN) • Private IP address used within private networks and internets • DHCP server has Dynamic Host Configuration Protocol (DHCP) to assign a temporary IP address for accessing the Internet • Network Address Translation (NAT): The process of changing public IP addresses into private IP addresses, and the reverse
Domain Name System • Convert user-friendly name into their IP address • domain name: any registered, valid name with ICANN • resolving the domain name: the process of changing a name into its IP address • ICANN has 13 computer as root servers for maintaining a list of IP addresses of servers to resolve each type of TLD in the world • Top-level domain (TLD) • Non-U.S. is the two letter abbreviation for the country • U.S. is the type of organization • Uniform resource locator (URL): document’s address on the Web • Domain name resolvers store the correspondence of domain names and IP address
IP Addressing Schemes • IPv4 and • IPv4 • 32 bits divided into four groups of 8 bits, and a decimal number represents each group • 63.224.57.59 • The largest decimal number between the period is 255 (0 – 255) • IPv6 • 128 bits due to the growth of the Internet • Currently both IPv4 and IPv6 are used on the Internet
Security • Encryption algorithms: DES, 3DES, AES • Key • Symmetric encryption • Asymmetric encryption: public key and private key • HTTPS • Secure Socket Layer (SSL) and Transport Layer Security (TLS) • Public key, private key and symmetric encryption
Summary • TCP/IP-OSI five layers • Application layer • Transport layer • Internet layer • Data link layer • Physical layer • Public switched data network (PSDN) • Dynamic Host Configuration Protocol (DHCP) to assign a temporary IP address for accessing the Internet • Domain name
Discussion • Problem solving (121a-b) • What are the new opportunities for the business generated by the Internet? • What are the new threats for the business generated by the Internet? • Opposing forces (129a-b) • State your opinions related to the negative impact on the society when everyone is connect through the Internet. • Security (133a-b) • State the impacts on the society and business from the government having an decryption method to decode everything over the Internet. • Ethics (141a-b) • State the impacts from the employee’s private usage of company’s computer facility. • Reflections (143a-b) • How should you react properly from not getting lost from this Internet age?
Case Study • Case 5-1 (148-149) Network Services: questions 1, 3, 4, 5, 6, 9, and 10
Points to Remember • Network Concepts • Communication Protocol • TCP/IP-OSI Architecture • Network Types • LAN • WAN • Public Switched Data Network • Virtual Private Network • Network Comparison • Internet • Domain Name System • IP Addressing Schemes • Security • Discussion and Case Study