Networking 101 english


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Networking 101 english

  1. 1. Networking 101 by : Eliran Ben-Zikri Welcome to the amazing world of computer networking, I hope you’ll find this presentation informative and interesting. Networking – A bunch of devices with cool green LEDs that when combined all together allows computers to exchange data
  2. 2. Networking 101 History 60,000 Years ago – People started to Speak 5,000 Years ago – People started to Write 600 Years ago – Please started to publish 50 Years ago – The Internet was born
  3. 3. Networking 101 History WWW was invented in 1989 by Tim Berners- Lee. The entire World-Wide-Web used to be just one computer
  4. 4. Networking 101 Facts In 1999, 38M People had broadband Internet. Today, 1.2B have in on their mobile devices
  5. 5. Networking 101 Facts 14.3 Trillion webpages are live on the Internet 2.7 Billion People (40% of the world’s population) are Online.
  6. 6. Internet? Say what? How did it all start? Back in the 70’s, many vendors developed many types of computers, each has it’s own set of protocols and architecture an IBM Computer could only talk to an IBM computer No standards, No compatibility TCP/IP & OSI model we’re combined to help creating the world you know today
  7. 7. OSI Model The Layers of the Internet The Open System Interconnect Model Wait, What?
  8. 8. OSI Model Key Principles Divides Networking to 7 Layers Each layer takes care of a very specific job Each Job is not too Complicated Passes the data onto the next layer. Defines “What”, Not “How”
  9. 9. OSI Model 1 Model To Rule Them All Application Presentation Session Transport Network Data Link Physical ‫האפליקציה‬ ‫שכבת‬ ‫התצוגה‬ ‫שכבת‬ ‫השיחה‬ ‫שכבת‬ ‫התובלה‬ ‫שכבת‬ ‫הרשת‬ ‫שכבת‬ ‫הערוץ‬ ‫שכבת‬ ‫פיזית‬ ‫שכבה‬
  10. 10. The physical layer does not understand anything but bits: The signal comes to it in the form of pulses and is transformed into 0's and 1's. Examples: Physical Equipment, Cables, Connectors, NICs Bit Sync, Work Rate Hubs, Repeaters, USB, Bluetooth, SDH, DSL Encoding Parallel VS. Serial OSI Model #1 - Physical Layer RCVTRS …110100101110010011101…
  11. 11. Puts some sense to the bits, turning them into Frames, Bridging between Layer 1 & 3 (LLC & MAC), Connecting between Hosts in the LAN – No IP’s, Just MAC’s. Examples: CRC – Error Handling ARP Table Collisions and Broadcasts MAC Addresses Switches, LAN, ATM, VLANs OSI Model #2 – Data-Link Layer 1 2 3 6 5 4
  12. 12. Responsible for packet forwarding, Routing, Transferring data from a source to a destination host via one or more networks, while maintaining Quality-Of-Service functions Connecting two or more LANs all together Examples: Inter-Networking (Internet = Collection of LANs 7 WANs) IP Protocol (Connectionless), ICMP, IPSec, IPX QOS, Routing Packets, WAN OSI Model #3 – Network Layer
  13. 13. Provides end-to-end communication services for applicationswithin a layered architecture of network components and protocols, Between Ports. Examples: Connects between Applications Reliabile/Unreliable Connection (VoIP vs HTTP) Flow Control Multiplexing TCP, UDP, Segments OSI Model #4 – Transport Layer
  14. 14. Provides the mechanism for opening, closing and managing a session between end-user application processes Examples: Full/Half Duplex Sync RPC, SCP OSI Model #5 – Session Layer
  15. 15. Responsible for the delivery and formatting of information to the application layer for further processing or display. Examples: Data Conversion Encryption & Decryption ASCII, Terminal, Telnet, AFP OSI Model #6 – Presentation Layer Value Code A 65 B 66 C 67 D 68 E 69 F 70
  16. 16. The user interface, Responsible for displaying data and images to the user in a human-recognizable format and to interface with the presentation layer below it. Examples: SSH, FTP, HTTP, SSL, DNS NFS, SIP, SMB, SMTP, RDP LDAP, POP, IMAP, SNMP REST, Web Applications OSI Model #7 – Application Layer
  17. 17. OSI Model Encapsulation Application Presentation Session Transport Network Data Link Physical Data Data Data DataTransport Header DataNetwork Header DataData Link Header Data
  18. 18. OSI Model #7 – Application Layer Application Presentation Session Transport Network Data Link Physical Application Presentation Session Transport Network Data Link PhysicalPhysical Data Link Network
  19. 19. Networking 101 DNS DNS – Domain Name Server/Service It translates easily memorized domain names  to the numerical IP addresses Hierarchical! -> -> Client Local Name Server Root Name Server IP IP Name Name
  20. 20. Networking 101 DNS Client Local Name Server Root Name Server IP IP Name Name
  21. 21. Networking 101 NAT NAT – Network Address Translation Private IP’s <-> Public IP’s One-to-One, One-to-Many Source NAT: In -> Out Destination NAT: Out -> In
  22. 22. Networking 101 VLAN VLAN – Virtual LAN Partitioning a Switch to several virtual networks A router is needed for Inter-LAN communication Software rather than Hardware Each Packet is tagged with A VLAN number, and Only Trunk ports or the same VLAN ports can accept these Frames (Layer 2)
  23. 23. Networking 101 Wireless Wi-Fi/WLAN based on IEEE 802.11 specs Uses wireless access points (WAPs) Usually operate in the unlicensed spectrum near 2.4 GHz. MIMO – Multiple Input, Multiple Output 802.11a 54Mbps max, 75 feet max, uses 5 GHz band - Rare 802.11b 11Mbps max, 45 meter max, 2.4 GHz, lowest cost – The Past 802.11g 54Mbps max, 45 meter max, 2.4 GHz band – The Popular 802.11n 600Mbps max, 70 meter max, 2.4 or 5 GHz band, MIMO – Rising 802.11ac 1Gbps max, 70 meter max, 5 GHz band, MIMO – The Future
  24. 24. Networking 101 The END Thank You for Listening! Wanna know more? Just ask. Contact me @