INTERNET INTRO version 1.1

Juha Söderqvist

Internet history – Sputnik 1

Internet history – Modem

Internet history – ARPA

Internet history - J.C.R. Licklider

Internet history - J.C.R. Licklider

Internet history – Packet-Switching

Internet history – Intergalactic Network

Internet history – ARPANET

Internet history – ASCII

Internet history – Hypertext

Internet history – Packet-Switching

Internet history – Packet-Switching

Internet history – WAN

Internet history – ARPAnet project

Internet history – ARPAnet design

Internet history – ARPAnet IMP

Internet history – Flight simulator

1967 Danny Cohen develops the first real-time visual flight simulator on a

general purpose computer and the first real-time radar simulator.

1967 – plans for ARPANET were published

Internet history – Engelbart

Internet history – Host Level Protocols

Internet history – First Data Packets

1969 UCLA Team Sends First Data Packets

The first data packets are sent between networked computers on October 29th by Charley Kline at UCLA, under supervision of Professor Leonard Kleinrock. The first attempt resulted in the system crashing as the letter G of “Login” was entered. The second attempt was successful.

Internet history – ARPANET 1969

Internet history – IMP Links

1969 IMP Network Links First Four Nodes

The physical Interface Message Processor (IMP) network is constructed, linking four nodes: University of California at Los Angeles, SRI (in Stanford), University of California at Santa Barbara, and University of Utah

Internet history – ARPANET 1972

1972 – 23 host computers 15 Nodes

Remote logins: With ARPANET, people could use one computer system to log into another one miles away. For the first time, researchers and scientists could access databases full of information without having to physically travel to another computer site. In 1971, ARPANET integrated the first Terminal Interface Processor (TIP), which enabled users at individual computer terminals to dial into the network

Internet history – Email

Internet history – Public

Internet history – IANA

Internet history – ARPANET 1973

Internet history – Ethernet

Internet history – TCP/IP

Internet history – TCP/IP

Internet history – International Link

Internet history – NIC

Internet history – “Internet”

Internet history – Telenet

Internet history – CSNET

Internet history – Routing Protocol

Internet history – Public WAN

Internet history – ARPAnet TCP/IP

Internet history – DNS

Internet history – Maxthink

Internet history – RIPE

Internet history – ISP

Internet history – IRC

Internet history – HyperRez

Internet history – HyperBBS

Internet history – WWW

Internet history – WAIS

Internet history – Browser

Internet history – EFF

Internet history – Linux

Internet history – Search Engine

Internet history – PGP

Internet history – Information Superhighway

Internet history – WWW public

Internet history – Lynx

Internet history – Cello

Internet history – Mosaic

Internet history – Netscape

Internet history – Javascript

Internet history – NES

Internet history – VBS,Jscript,IIS

Internet history – Blogs, wikipedia

Internet definition

Network defintion

Networking models

Networking models

Networking models - OSI

OSI Model Vs TCP/IP Model

TCP/IP History

TCP/IP Model

TCP/IP IP address

  • IP: CLASS A, B, C
  • Static IP

    TCP/IP Communication Example

    1. Enter website in browser

    2. DNS client creates a message

    DNS client sends a message to the Transport layer requesting the IP address for website.com

    3. Create a datagram

    The Transport layer adds the UDP header containing the source and destination port to the

    message.

    4. Create a packet

    The Network layer adds the IP header containing the source and destination IP address

    to the datagram.

    It adds its own IP address as the source and the DNS server IP address as the destination.

    The PC knows the DNS server’s IP address because the router provided the PC with it

    when it assigned its local IP address. The resulting packet is sent to the Link layer.

    5. Determine destination MAC address

    The Link layer determines the destination IP address for this packet is not on the local network.

    It therefore needs to send the packet to its “default gateway” which in this example is the router.

    The Link Layer can’t create the frame because it doesn’t know the MAC address for the default

    gateway. The Address Resolution Protocol or ARP was created to solve this problem.

    6. Create and transmit a frame

    After using ARP to get the MAC address for its default gateway, the Link Layer can

    complete the frame for the DNS transaction.

    It adds the source and destination MAC addresses to the packet to create a frame.

    The source MAC address is its own and the destination MAC address is that of the dgw.

    This frame is then sent to the Physical layer to transmit the frame’s bits.

    7. NAT and forward frame to Internet

    The router receives the frame from the PC, opens the packet and determines the destination

    IP address is not on the local network, so it must forward this frame to the Internet.

    The router has to change the source MAC from its local network MAC to its Wide Area Network.

    The local router forwards this new frame to the ISP's router.

    8. Forward frame to DNS server

    The router at the Internet Service Provider receives the frame and opens the packet to find the

    destination IP address. It determines the destination IP address belongs to its DNS server.

    9. DNS server receives frame

    The DNS server’s PHY receives the bits and forwards the frame to the Link layer.

    The Link layer finds its MAC address as the destination so it forwards the packet to the

    Network layer. The Network layer opens the packet and finds its IP address as the destination.

    It still needs to pay attention to the message, so it forwards it up to the Transport layer.

    The Transport layer opens the datagram and finds it is being sent to port 53. The DNS server

    has a process running and listening for traffic on this port, so the message is forwarded to it.

    10. DNS translates and generates reply

    DNS Server determines the IP address for website.com and generates a reply

    message containing it. The message is sent back to the Transport layer.

    The Transport layer adds the port information and creates the datagram.

    The Network layer adds the IP information and creates the packet.

    The Link layer adds the MAC information and creates the frame.

    The Physical layer transmits the frame’s bits to the router.

    11. Forward frame to local router

    The ISP’s router receives the frame, finds its MAC address, and sends it to its Network layer to

    determine the destination IP address. It finds that the packet belongs to our local router’s IP

    address, so it sends the packet back down to its Link layer.

    The Link layer attaches new source and destination MAC addresses to the packet then

    sends the frame to our local router.

    12. NAT translation in local router

    When the local router receives the packet from the ISP’s router, it consults its NAT translation

    table to determine which local host to forward it to. It finds an entry with an internet destination

    port number of “1” in the translation table. The corresponding local IP address and port # are

    substituted into the packet that will be sent to the local network.

    13. Frame forwarded to PC

    The new packet is sent to the router’s Link layer where the source and destination MAC addresses are added creating the frame.

    The router knows the destination MAC address corresponding to the destination IP address by

    consulting its ARP table. This frame is then sent to the physical layer to be transmitted on the

    network.

    14. DNS client delivers IP address

    When the Frame arrives at the PC the message is sent to the DNS client.

    The DNS client then provides the IP address for website.com to the HTTP client.

    15. HTTP client creates message

    Now that the HTTP client has the IP address for website.com (130:27:45:69) it can generate the

    message to download the HTML file for this website.

    HTTP Client Request

    HTTP Server response

    HTTP status codes 1xx

    HTTP status codes 2xx

    HTTP status codes 3xx

    HTTP status codes 4xx

    URL = Uniform Resource Locator

    URL = Uniform Resource Locator

    URL = Uniform Resource Locator

    URL/URI

    Uniform Resource Identifier - URI

    Uniform Resource Name - URN

    ICMP / PING


    (C)2017 Juha Soderqvist