Internet history, Technology and Security (Week 2)

Week 2history:the First Internet-nsfnet

Welcome to Week 2! This week, we'll be covering the history of the first internet:nsfnet. In the 1960s and 1970s, there is a great deal of the-do to build the first Wide-area packet switched networks for The US Department of Defense. In the 1980s, the first ' Internet ' is formed to allow academic researchers to access supercomputer resources.

Supercomputers Justify a national networkhistory Through supercomputing

Several network modes are described in this section of the video.
1.Data Transfer with leased Lines
Leased Lines: fixed-line (short line) is used to connect two regions of the symmetrical telecommunications lines. Unlike the traditional PSTN, the leased line does not have a phone number, and both ends of the leased line are created with a permanent connection. Dedicated lines can be used in telephones, data and internet services. Its cost is based on distance, rather expensive.

2.Store and Forward Networking
The use of bitnet can reduce the cost of the telephone line (because it is too expensive to communicate using a leased line). But as demonstrated in the video, the data sent and the data sent by others need to be queued in the network. The route created by the sender and receiver is not a 2.1-wire (this is too expensive), but rather a network of nodes is set up between them to forward.
The disadvantage is that if you send a large file to be transmitted in a long time (because of the continuous, so the same time can only be transmitted on a link), which will affect the later you want to send the file, which affects efficiency. The following arpanet consider dividing large files into slices, which can improve efficiency. In the video, a simple demonstration of the storage and forwarding principle.

3.ARPANET
(Wiki) Senior Research Programme network (English: Advanced Studies Projects Agency Network, abbreviated ARPANET) is the world's first operational packet switching network developed by the U.S. Defense Advanced Research Programme, and is the originator of the global Internet.
ARPANET uses a "packet switching technology" (Packet switching technology). The so-called "Packet Exchange Theory" is to separate each piece of information into a fixed size block "packaging", each package is indicated where from, where to pass. For example I want to teleport "I had a good friend and I like him.", it can be divided into 2 parts (packages), and marked with serial number, and then carried out separately (can be transferred in different links---is to be centralized, because you do not know the specific direction of these packages). Finally, the receiving party accepts and stitching these small parts according to the serial number, and finally composes the complete information.
Here's an example of a problem: If your package is being forwarded over the network, there's a "beat-around" behavior.

Larry SMARR-NCSA

This section describes Larry Smarr. He is a relativistic astrophysicist who engages in questions of astrophysics, such as general relativity, gas dynamics, and so on. The study of this astrophysical problem required a complex and high-speed computer, so he began to invest in this aspect = =. Larry Smarr persuaded Congress to authorize the use of supercomputers and persuaded Congress to pay for the National Science Foundation Network, using ARPANET's TCP/IP network protocol. Can be said to a certain extent to promote the construction of the network.

The first "Internet" History Through NSFNet

Because of the strategic mistakes, the University of Michigan was not involved in ARPANET's work, and they established their own network---NSFNet. Let Doug Van houweling introduce us here!

Doug Van houweling-nsfnet

Doug Van Houweling thinks that, for the University of Michigan, it's better to run a network that connects all supercomputing centers than having a supercomputer. The National Security Fund Program, which lasts 5 years and costs $15 million, can only create a 56,000-bit network (too small and easily clogged), and what is the best network? So he got in touch with Jamie Andsaid, and they reached an agreement with IBM that IBM would provide hardware and software to create a routing structure for the network. At the time of the MCI and T-T confrontation, Dick Liebhaber, the chief executive of MCI, worked with Doug van to propose a valuable joint proposal for a nationwide communications facility. His design is not 56,000-bit, but begins with 1.5 megabits. It was not long before TCP/IP was present, and the proposal received suspicions from the National Science Foundation of the United States. But traffic explains everything (this network is growing in the form of explosions!) ), thanks to the TCP/IP protocol.

They then entered the next phase, DS3, with a 30 times-fold increase in network design (compared to 1.5 megabits), which reached 45 megabits. They created another nonprofit organization---NSF network, which is currently the fastest Internet network (retired in 95).

Leonard klienrock-the First and Packets on the Internet

Welcome to the University of California, Los Angeles Bolt Hall! Pave the doorway. These represent 0 or 1 tiles, and this string represents the ASCII character. On October 29, 1969, from UCLA to the Stanford Institute (Stanford Research Institute), the two packets of "L" and "O" were transmitted between them.

Requirements for shared resources: The University of Illinois believes that there is a need to create a network that can share resources (so that it meets the needs of its fellows ...). ), so Leonard and the other few began to design, test. Herb Baskin proposed to send short messages within a short period of time, for example, within 200 milliseconds, Westclock said, to separate computers from communications and so on. So they started their experiment at UCLA, and eight months later, they got the new technology, new equipment.
So, Leonard and Charlie Klein, Bill Duvall began the experiment:
Charlie:you get the L?
Bill:yep, got the L.
Charlie:get the O?
Bill:got the O.
Get the G, crash! (then they tried to log in)
IMP number--UCLA, a Honeywell mini computer, is adapted by Bolt,beranek and NEWMAN,BBN. It is the first device on the internet!

Katie hafner-where Wizards Stay up late

Katie Hafner is a journalist who wrote articles about technology, health and society in the New York Times. Interviewed a lot of big guy.

Ray Tomlinson, who implemented the first e-mail system on the ARPANET system in 1971, invented the @ symbol, the first system to send mail between different host users connected to Arpane.
Jon Postel: Invented the domain Name System.

Summary

This week's content mainly introduces the continuous development of the network transmission mode, and in 1969 experimented with the transmission of the packet! Since then the development of the network, from scratch, from small to the current explosion of the global network, exclamation technology development too fast.

Internet history, Technology and Security (Week 2)