==Phrack Inc.== Volume Three, Issue 27, File 3 of 12 <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> <> <> <> Introduction to MIDNET <> <> ~~~~~~~~~~~~~~~~~~~~~~ <> <> Chapter Seven Of The Future Transcendent Saga <> <> <> <> A More Indepth Look Into NSFnet <> <> National Science Foundation Network <> <> <> <> Presented by Knight Lightning <> <> June 16, 1989 <> <> <> <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> Prologue ~~~~~~~~ If you are not already familiar with NSFnet, I would suggest that you read: "Frontiers" (Phrack Inc., Volume Two, Issue 24, File 4 of 13), and definitely; "NSFnet: National Science Foundation Network" (Phrack Inc., Volume Three, Issue 26, File 4 of 11). Table Of Contents ~~~~~~~~~~~~~~~~~ * Introduction * The DOD Protocol Suite * Names and Addresses In A Network * Telnet (*NOT* Telenet) * File Transfer * Mail Introduction ~~~~~~~~~~~~ MIDNET is a regional computer network that is part of the NSFnet, the National Science Foundation Network. Currently, eleven mid-United States universities are connected to each other and to the NSFnet via MIDnet: UA - University of Arkansas at Fayetteville ISU - Iowa State University at Ames UI - University of Iowa at Iowa City KSU - Kansas State University at Manhattan KU - University of Kansas at Lawrence UMC - University of Missouri at Columbia WU - Washington University at St. Louis, Missouri UNL - University of Nebraska at Lincoln OSU - Oklahoma State University at Stillwater UT - University of Tulsa (Oklahoma) OU - University of Oklahoma at Norman Researchers at any of these universities that have funded grants can access the six supercomputer centers funded by the NSF: John Von Neuman Supercomputer Center National Center for Atmospheric Research Cornell National Supercomputer Facility National Center for Supercomputing Applications Pittsburgh Supercomputing Center San Diego Supercomputing Center In addition, researchers and scientists can communicate with each other over a vast world-wide computer network that includes the NSFnet, ARPAnet, CSnet, BITnet, and others that you have read about in The Future Transcendent Saga. Please refer to "Frontiers" (Phrack Inc., Volume Two, Issue 24, File 4 of 13) for more details. MIDnet is just one of several regional computer networks that comprise the NSFnet system. Although all of these regional computer networks work the same, MIDnet is the only one that I have direct access to and so this file is written from a MIDnet point of view. For people who have access to the other regional networks of NSFnet, the only real differences depicted in this file that would not apply to the other regional networks are the universities that are served by MIDnet as opposed to: NYSERnet in New York State SURAnet in the southeastern United States SEQSUInet in Texas BARRnet in the San Francisco area MERIT in Michigan (There are others that are currently being constructed.) These regional networks all hook into the NSFnet backbone, which is a network that connects the six supercomputer centers. For example, a person at Kansas State University can connect with a supercomputer via MIDnet and the NSFnet backbone. That researcher can also send mail to colleagues at the University of Delaware by using MIDnet, NSFnet and SURAnet. Each university has its own local computer network which connects on-campus computers as well as providing a means to connecting to a regional network. Some universities are already connected to older networks such as CSnet, the ARPAnet and BITnet. In principal, any campus connected to any of these networks can access anyone else in any other network since there are gateways between the networks. Gateways are specialized computers that forward network traffic, thereby connecting networks. In practice, these wide-area networks use different networking technology which make it impossible to provide full functionality across the gateways. However, mail is almost universally supported across all gateways, so that a person at a BITnet site can send mail messages to a colleague at an ARPAnet site (or anywhere else for that matter). You should already be somewhat familiar with this, but if not refer to; "Limbo To Infinity" (Phrack Inc., Volume Two, Issue 24, File 3 of 13) and "Internet Domains" (Phrack Inc., Volume Three, Issue 26, File 8 of 11) Computer networks rely on hardware and software that allow computers to communicate. The language that enables network communication is called a protocol. There are many different protocols in use today. MIDnet uses the TCP/IP protocols, also known as the DOD (Department of Defense) Protocol Suite. Other networks that use TCP/IP include ARPAnet, CSnet and the NSFnet. In fact, all the regional networks that are linked to the NSFnet backbone are required to use TCP/IP. At the local campus level, TCP/IP is often used, although other protocols such as IBM's SNA and DEC's DECnet are common. In order to communicate with a computer via MIDnet and the NSFnet, a computer at a campus must use TCP/IP directly or use a gateway that will translate its protocols into TCP/IP. The Internet is a world-wide computer network that is the conglomeration of most of the large wide area networks, including ARPAnet, CSnet, NSFnet, and the regionals, such as MIDnet. To a lesser degree, other networks such as BITnet that can send mail to hosts on these networks are included as part of the Internet. This huge network of networks, the Internet, as you have by now read all about in the pages of Phrack Inc., is a rapidly growing and very complex entity that allows sophisticated communication between scientists, students, government officials and others. Being a part of this community is both exciting and challenging. This chapter of the Future Transcendent Saga gives a general description of the protocols and software used in MIDnet and the NSFNet. A discussion of several of the more commonly used networking tools is also included to enable you to make practical use of the network as soon as possible. The DOD Protocol Suite ~~~~~~~~~~~~~~~~~~~~~~ The DOD Protocol Suite includes many different protocols. Each protocol is a specification of how communication is to occur between computers. Computer hardware and software vendors use the protocol to create programs and sometimes specialized hardware in order to implement the network function intended by the protocol. Different implementations of the same protocol exist for the varied hardware and operating systems found in a network. The three most commonly used network functions are: Mail -- Sending and receiving messages File Transfer -- Sending and receiving files Remote Login -- Logging into a distant computer Of these, mail is probably the most commonly used. In the TCP/IP world, there are three different protocols that realize these functions: SMTP -- (Simple Mail Transfer Protocol) Mail FTP -- (File Transfer Protocol) sending and receiving files Telnet -- Remote login How to use these protocols is discussed in the next section. At first glance, it is not obvious why these three functions are the most common. After all, mail and file transfer seem to be the same thing. However, mail messages are not identical to files, since they are usually comprised of only ASCII characters and are sequential in structure. Files may contain binary data and have complicated, non-sequential structures. Also, mail messages can usually tolerate some errors in transmission whereas files should not contain any errors. Finally, file transfers usually occur in a secure setting (i.e. The users who are transferring files know each other's names and passwords and are permitted to transfer the file, whereas mail can be sent to anybody as long as their name is known). While mail and transfer accomplish the transfer of raw information from one computer to another, Telnet allows a distant user to process that information, either by logging in to a remote computer or by linking to another terminal. Telnet is most often used to remotely log in to a distant computer, but it is actually a general-purpose communications protocol. I have found it incredibly useful over the last year. In some ways, it could be used for a great deal of access because you can directly connect to another computer anywhere that has TCP/IP capabilities, however please note that Telnet is *NOT* Telenet. There are other functions that some networks provide, including the following: - Name to address translation for networks, c...
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