Layer 8 is a term used to refer to "user" or "political" layer on top of the 7-layer OSI model of computer networking. The OSI model is a 7-layer abstract model that describes an architecture of data communications for networked computers; the layers build upon each other. The top layer is the Application Layer describing protocols of software applications, it is held that the user is the 8th layer. Network appliances vendor like Cyberoam claim that Layer 8 allows IT administrators to identify users, control Internet activity of users in the network, set user based policies and generate reports by username. According to Bruce Schneier and RSA: Layer 8: The individual person. Layer 9: The organization. Layer 10: Government or legal complianceSince the OSI layer numbers are used to discuss networking topics, a troubleshooter may describe an issue caused by a user to be a layer 8 issue, similar to the PEBKAC acronym, the ID-Ten-T Error and PICNIC. Political economic theory holds. Political policies such as network neutrality, spectrum management, digital inclusion all shape the technologies comprising layers 1-7 of the OSI Model.
An 8th layer has been referenced to physical controllers containing an external hardware device which interacts with an OSI model network. An example of this is ALI in Profibus. A network guru T-shirt from the 1980s shows Layer 8 as the "financial" layer, Layer 9 as the "political" layer; the design was credited to Evi Nemeth. In the TCP/IP model, the 4-layer model of the Internet, the 5th layer is analogously sometimes described as the political layer; this appears in RFC 2321, a humorous April Fools' Day RFC published in 1998. Linux Gazette carries a regular column called Layer 8 Linux Security. Layers 8, 9, 10 are sometimes used to represent individuals and governments for the user layer of Service Oriented Architectures. See OSI User Layers figure for details. User-in-the-loop is a serious concept including Layer 8 as a system level model. In 2016, a company shipped a product called Layer8 to "bridge the universal divide between PC users and IT managers". IRL Liveware
On the Internet, a block or ban is a technical measure intended to restrict access to information or resources. Blocking and its inverse, may be implemented by the owners of computers using software; some countries, including China and Singapore, block access to certain news information. In the United States, the Children's Internet Protection Act requires schools receiving federal funded discount rates for Internet access to install filter software that blocks obscene content, and, where applicable, content "harmful to minors". Blocking may refer to denying access to a web server based on the IP address of the client machine. In certain websites, including social networks such as Facebook or editable databases like Wikimedia projects and other wikis, users can apply blocks on other users deemed undesirable to prevent them from performing certain actions. Blocks of this kind may occur for several reasons and produce different effects: in social networks, users can unrestrictedly block other users by preventing them from sending messages or viewing the blocker's information or profile.
Privileged users can apply blocks. Blocking is used by moderators and administrators of social media and forums to deny access to users that have broken their rules and will do so again, in order to ensure a peaceful and orderly discussion place. Common reasons for blocking are spamming and flaming; some criticize cases of the use of bans by administrators of large websites, such as Twitter, saying that these bans may be politically or financially motivated. However, websites have a legal right to decide, allowed to post, users respond by "voting with their feet" and going to a place where the administrators see their behavior as acceptable. Blocked users may be unable to access all or part of a site's content, the case when censoring or filtering mechanisms are responsible for the block. Under a shadow ban, a user is given the false impression that their content is still being posted to the site, when in reality it is being hidden from all other users. Ban evasion is the act of attempting to get around a ban, whether temporary or permanent, on a website.
Alternate accounts set up by people evading bans from websites are referred to as sockpuppets. If someone is caught evading a ban with a sockpuppet, the sockpuppet account is banned. If the original ban was temporary, it may be extended or made permanent. Sometimes, the user's IP address may be banned as well so the user cannot access the site or create new accounts; some sites may remove all but a few traces of the ban-evader. TV Tropes and Wikipedia, for example, may mass-delete any pages created by a ban-evader. Ban evasion can be detected by tracing a user's IP address. If two accounts are using the same IP address, it could be a sign of ban evasion; the use of a VPN, shown by rapid, drastic changes of IP address by the same user in a short period of time, can be a sign that the user was trying to get around a ban. Ban evasion can be spotted if posts or other contributions from two accounts look the same or similar, or on sites where the same email can be associated with multiple accounts, identical or similar emails can be a sign of ban evasion.
Users who have been permanently banned for ban evasion may not be able to appeal their ban, the case on sites such as TV Tropes. When creating sockpuppets, ban evaders use a variety of tactics to disguise the fact that the new account was created by a banned user, such as using new names, an alternate email address, VPNs or proxy servers to mask their IP address, changing their IP address, or using the site from public Internet access locations such as schools and libraries. Ban Internet censorship IP blocking Shadow banning
Internet Relay Chat
Internet Relay Chat is an application layer protocol that facilitates communication in the form of text. The chat process works on a client/server networking model. IRC clients are computer programs that users can install on their system or web based applications running either locally in the browser or on 3rd party server; these clients communicate with chat servers to transfer messages to other clients. IRC is designed for group communication in discussion forums, called channels, but allows one-on-one communication via private messages as well as chat and data transfer, including file sharing. Client software is available for every major operating system; as of April 2011, the top 100 IRC networks served more than half a million users at a time, with hundreds of thousands of channels operating on a total of 1,500 servers out of 3,200 servers worldwide. IRC usage has been declining since 2003, losing 60% of its users and half of its channels. IRC was created by Jarkko Oikarinen in August 1988 to replace a program called MUT on a BBS called OuluBox at the University of Oulu in Finland, where he was working at the Department of Information Processing Science.
Jarkko intended to extend the BBS software he administered, to allow news in the Usenet style, real time discussions and similar BBS features. The first part he implemented was the chat part, which he did with borrowed parts written by his friends Jyrki Kuoppala and Jukka Pihl; the first IRC network was running on a single server named tolsun.oulu.fi. Oikarinen found inspiration in a chat system known as Bitnet Relay, which operated on the BITNET. Jyrki Kuoppala pushed Jarkko to ask Oulu University to free the IRC code so that it could be run outside of Oulu, after they got it released, Jyrki Kuoppala installed another server; this was the first "irc network". Jarkko got some friends at the Helsinki University and Tampere University to start running IRC servers when his number of users increased and other universities soon followed. At this time Jarkko realized that the rest of the BBS features wouldn't fit in his program. Jarkko got in touch with people at the University of Oregon State University.
They wanted to connect to the Finnish network. They had obtained the program from one of Jarkko's friends, Vijay Subramaniam—the first non-Finnish person to use IRC. IRC grew larger and got used on the entire Finnish national network—Funet—and connected to Nordunet, the Scandinavian branch of the Internet. In November 1988, IRC had spread across the Internet and in the middle of 1989, there were some 40 servers worldwide. In August 1990, the first major disagreement took place in the IRC world; the "A-net" included a server named eris.berkeley.edu. It required no passwords and had no limit on the number of connects; as Greg "wumpus" Lindahl explains: "it had a wildcard server line, so people were hooking up servers and nick-colliding everyone". The "Eris Free Network", EFnet, made the eris machine the first to be Q-lined from IRC. In wumpus' words again: "Eris refused to remove that line, it wasn't much of a fight. A-net was formed with the eris servers, EFnet was formed with the non-eris servers.
History showed most users went with EFnet. Once ANet disbanded, the name EFnet became meaningless, once again it was the one and only IRC network, it is around that time that IRC was used to report on the 1991 Soviet coup d'état attempt throughout a media blackout. It was used in a similar fashion during the Gulf War. Chat logs of these and other events are kept in the ibiblio archive. Another fork effort, the first that made a big and lasting difference, was initiated by'Wildthang' in the U. S. October 1992, it was meant to be just a test network to develop bots on but it grew to a network "for friends and their friends". In Europe and Canada a separate new network was being worked on and in December the French servers connected to the Canadian ones, by the end of the month, the French and Canadian network was connected to the US one, forming the network that came to be called "The Undernet"; the "undernetters" wanted to take ircd further in an attempt to make it less bandwidth consumptive and to try to sort out the channel chaos that EFnet started to suffer from.
For the latter purpose, the Undernet implemented timestamps, new routing and offered the CService—a program that allowed users to register channels and attempted to protect them from troublemakers. The first server list presented, from February 15, 1993, includes servers from USA, France and Japan. On August 15, the new user count record was set to 57 users. In May 1993, RFC 1459 was published and details a simple protocol for client/server operation, one-to-one and one-to-many conversations, it is notable that a significant number of extensions like CTCP, colors and formats are not included in the protocol specifications, nor is character encoding, which led various implementations of servers and clients to diverge. In fact, software implementation varied from one network to the other, each network implementing their own policies and standards in their own code bases. During the summer of 1994, the Undernet was itself forked; the new network was called DALnet, formed for better user service and more user and channel protections.
One of the more significant changes in DALnet was use of lo
Usenet is a worldwide distributed discussion system available on computers. It was developed from the general-purpose Unix-to-Unix Copy dial-up network architecture. Tom Truscott and Jim Ellis conceived the idea in 1979, it was established in 1980. Users post messages to one or more categories, known as newsgroups. Usenet resembles a bulletin board system in many respects and is the precursor to Internet forums that are used today. Discussions are threaded, as with web forums and BBSs, though posts are stored on the server sequentially; the name comes from the term "users network". A major difference between a BBS or web forum and Usenet is the absence of a central server and dedicated administrator. Usenet is distributed among a large changing conglomeration of servers that store and forward messages to one another in so-called news feeds. Individual users may read messages from and post messages to a local server operated by a commercial usenet provider, their Internet service provider, employer, or their own server.
Usenet is culturally significant in the networked world, having given rise to, or popularized, many recognized concepts and terms such as "FAQ", "flame", "spam". Usenet was conceived in 1979 and publicly established in 1980, at the University of North Carolina at Chapel Hill and Duke University, over a decade before the World Wide Web went online and the general public received access to the Internet, making it one of the oldest computer network communications systems still in widespread use, it was built on the "poor man's ARPANET", employing UUCP as its transport protocol to offer mail and file transfers, as well as announcements through the newly developed news software such as A News. The name Usenet emphasized its creators' hope that the USENIX organization would take an active role in its operation; the articles that users post to Usenet are organized into topical categories known as newsgroups, which are themselves logically organized into hierarchies of subjects. For instance, sci.math and sci.physics are within the sci.* hierarchy, for science.
Or, talk.origins and talk.atheism are in the talk.* hierarchy. When a user subscribes to a newsgroup, the news client software keeps track of which articles that user has read. In most newsgroups, the majority of the articles are responses to some other article; the set of articles that can be traced to one single non-reply article is called a thread. Most modern newsreaders display the articles arranged into subthreads; when a user posts an article, it is only available on that user's news server. Each news server talks to one or more other exchanges articles with them. In this fashion, the article is copied from server to server and should reach every server in the network; the peer-to-peer networks operate on a similar principle, but for Usenet it is the sender, rather than the receiver, who initiates transfers. Usenet was designed under conditions when networks were not always available. Many sites on the original Usenet network would connect only once or twice a day to batch-transfer messages in and out.
This is because the POTS network was used for transfers, phone charges were lower at night. The format and transmission of Usenet articles is similar to that of Internet e-mail messages; the difference between the two is that Usenet articles can be read by any user whose news server carries the group to which the message was posted, as opposed to email messages, which have one or more specific recipients. Today, Usenet has diminished in importance with respect to Internet forums, mailing lists and social media. Usenet differs from such media in several ways: Usenet requires no personal registration with the group concerned; the groups in alt.binaries are still used for data transfer. Many Internet service providers, many other Internet sites, operate news servers for their users to access. ISPs that do not operate their own servers directly will offer their users an account from another provider that operates newsfeeds. In early news implementations, the server and newsreader were a single program suite, running on the same system.
Today, one uses separate newsreader client software, a program that resembles an email client but accesses Usenet servers instead. Some clients such as Mozilla Thunderbird and Outlook Express provide both abilities. Not all ISPs run news servers. A news server is one of the most difficult Internet services to administer because of the large amount of data involved, small customer base, a disproportionately high volume of customer support incidents; some ISPs outsource news operation to specialist sites, which will appear to a user as though the ISP ran the server itself. Many sites carry a restricted newsfeed, with a limited number of newsgroups. Omitted from such a newsfeed are foreign-language newsgroups and the alt.binaries hierarchy which carries software, music and images, accounts for over 99 percent of article data. There are Usenet providers that specialize in offering service to users whose ISPs do not carry news, or that carry a restricted feed. See news server operation for an overview of how news systems are implemented.
Newsgroups are accessed with newsreaders: applications that allow users to read and reply to postings in newsgro
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university in Cambridge, Massachusetts. Founded in 1861 in response to the increasing industrialization of the United States, MIT adopted a European polytechnic university model and stressed laboratory instruction in applied science and engineering; the Institute is a land-grant, sea-grant, space-grant university, with a campus that extends more than a mile alongside the Charles River. Its influence in the physical sciences and architecture, more in biology, linguistics and social science and art, has made it one of the most prestigious universities in the world. MIT is ranked among the world's top universities; as of March 2019, 93 Nobel laureates, 26 Turing Award winners, 8 Fields Medalists have been affiliated with MIT as alumni, faculty members, or researchers. In addition, 58 National Medal of Science recipients, 29 National Medals of Technology and Innovation recipients, 50 MacArthur Fellows, 73 Marshall Scholars, 45 Rhodes Scholars, 41 astronauts, 16 Chief Scientists of the US Air Force have been affiliated with MIT.
The school has a strong entrepreneurial culture, the aggregated annual revenues of companies founded by MIT alumni would rank as the tenth-largest economy in the world. MIT is a member of the Association of American Universities. In 1859, a proposal was submitted to the Massachusetts General Court to use newly filled lands in Back Bay, Boston for a "Conservatory of Art and Science", but the proposal failed. A charter for the incorporation of the Massachusetts Institute of Technology, proposed by William Barton Rogers, was signed by the governor of Massachusetts on April 10, 1861. Rogers, a professor from the University of Virginia, wanted to establish an institution to address rapid scientific and technological advances, he did not wish to found a professional school, but a combination with elements of both professional and liberal education, proposing that: The true and only practicable object of a polytechnic school is, as I conceive, the teaching, not of the minute details and manipulations of the arts, which can be done only in the workshop, but the inculcation of those scientific principles which form the basis and explanation of them, along with this, a full and methodical review of all their leading processes and operations in connection with physical laws.
The Rogers Plan reflected the German research university model, emphasizing an independent faculty engaged in research, as well as instruction oriented around seminars and laboratories. Two days after MIT was chartered, the first battle of the Civil War broke out. After a long delay through the war years, MIT's first classes were held in the Mercantile Building in Boston in 1865; the new institute was founded as part of the Morrill Land-Grant Colleges Act to fund institutions "to promote the liberal and practical education of the industrial classes" and was a land-grant school. In 1863 under the same act, the Commonwealth of Massachusetts founded the Massachusetts Agricultural College, which developed as the University of Massachusetts Amherst. In 1866, the proceeds from land sales went toward new buildings in the Back Bay. MIT was informally called "Boston Tech"; the institute adopted the European polytechnic university model and emphasized laboratory instruction from an early date. Despite chronic financial problems, the institute saw growth in the last two decades of the 19th century under President Francis Amasa Walker.
Programs in electrical, chemical and sanitary engineering were introduced, new buildings were built, the size of the student body increased to more than one thousand. The curriculum drifted with less focus on theoretical science; the fledgling school still suffered from chronic financial shortages which diverted the attention of the MIT leadership. During these "Boston Tech" years, MIT faculty and alumni rebuffed Harvard University president Charles W. Eliot's repeated attempts to merge MIT with Harvard College's Lawrence Scientific School. There would be at least six attempts to absorb MIT into Harvard. In its cramped Back Bay location, MIT could not afford to expand its overcrowded facilities, driving a desperate search for a new campus and funding; the MIT Corporation approved a formal agreement to merge with Harvard, over the vehement objections of MIT faculty and alumni. However, a 1917 decision by the Massachusetts Supreme Judicial Court put an end to the merger scheme. In 1916, the MIT administration and the MIT charter crossed the Charles River on the ceremonial barge Bucentaur built for the occasion, to signify MIT's move to a spacious new campus consisting of filled land on a mile-long tract along the Cambridge side of the Charles River.
The neoclassical "New Technology" campus was designed by William W. Bosworth and had been funded by anonymous donations from a mysterious "Mr. Smith", starting in 1912. In January 1920, the donor was revealed to be the industrialist George Eastman of Rochester, New York, who had invented methods of film production and processing, founded Eastman Kodak. Between 1912 and 1920, Eastman donated $20 million in cash and Kodak stock to MIT. In the 1930s, President Karl Taylor Compton and Vice-President Vannevar Bush emphasized the importance of pure sciences like physics and chemistry and reduced the vocational practice required in shops and drafting studios; the Compton reforms "renewed confidence in the ability of the Institute to develop leadership in science as well as in engineering". Unlike Ivy League schools, MIT catered more to middle-class families, depended more on tuition than on endow
Unix is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, development starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, others. Intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Microsoft, IBM, Sun Microsystems. In the early 1990s, AT&T sold its rights in Unix to Novell, which sold its Unix business to the Santa Cruz Operation in 1995; the UNIX trademark passed to The Open Group, a neutral industry consortium, which allows the use of the mark for certified operating systems that comply with the Single UNIX Specification. As of 2014, the Unix version with the largest installed base is Apple's macOS. Unix systems are characterized by a modular design, sometimes called the "Unix philosophy"; this concept entails that the operating system provides a set of simple tools that each performs a limited, well-defined function, with a unified filesystem as the main means of communication, a shell scripting and command language to combine the tools to perform complex workflows.
Unix distinguishes itself from its predecessors as the first portable operating system: the entire operating system is written in the C programming language, thus allowing Unix to reach numerous platforms. Unix was meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmers; the system grew larger as the operating system started spreading in academic circles, as users added their own tools to the system and shared them with colleagues. At first, Unix was not designed to be multi-tasking. Unix gained portability, multi-tasking and multi-user capabilities in a time-sharing configuration. Unix systems are characterized by various concepts: the use of plain text for storing data; these concepts are collectively known as the "Unix philosophy". Brian Kernighan and Rob Pike summarize this in The Unix Programming Environment as "the idea that the power of a system comes more from the relationships among programs than from the programs themselves".
In an era when a standard computer consisted of a hard disk for storage and a data terminal for input and output, the Unix file model worked quite well, as I/O was linear. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, semaphores, network sockets were added to support communication with other hosts; as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. By the early 1980s, users began seeing Unix as a potential universal operating system, suitable for computers of all sizes; the Unix environment and the client–server program model were essential elements in the development of the Internet and the reshaping of computing as centered in networks rather than in individual computers. Both Unix and the C programming language were developed by AT&T and distributed to government and academic institutions, which led to both being ported to a wider variety of machine families than any other operating system.
Under Unix, the operating system consists of many libraries and utilities along with the master control program, the kernel. The kernel provides services to start and stop programs, handles the file system and other common "low-level" tasks that most programs share, schedules access to avoid conflicts when programs try to access the same resource or device simultaneously. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space - although in microkernel implementations, like MINIX or Redox, functions such as network protocols may run in user space; the origins of Unix date back to the mid-1960s when the Massachusetts Institute of Technology, Bell Labs, General Electric were developing Multics, a time-sharing operating system for the GE-645 mainframe computer. Multics featured several innovations, but presented severe problems. Frustrated by the size and complexity of Multics, but not by its goals, individual researchers at Bell Labs started withdrawing from the project.
The last to leave were Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna, who decided to reimplement their experiences in a new project of smaller scale. This new operating system was without organizational backing, without a name; the new operating system was a single-tasking system. In 1970, the group coined the name Unics for Uniplexed Information and Computing Service, as a pun on Multics, which stood for Multiplexed Information and Computer Services. Brian Kernighan takes credit for the idea, but adds that "no one can remember" the origin of the final spelling Unix. Dennis Ritchie, Doug McIlroy, Peter G. Neumann credit Kernighan; the operating system was written in assembly language, but in 1973, Version 4 Unix was rewritten in C. Version 4 Unix, still had many PDP-11 dependent codes, is not suitable for porting; the first port to other platform was made five years f
A system administrator, or sysadmin, is a person, responsible for the upkeep and reliable operation of computer systems. The system administrator seeks to ensure that the uptime, performance and security of the computers they manage meet the needs of the users, without exceeding a set budget when doing so. To meet these needs, a system administrator may acquire, install, or upgrade computer components and software. Many organizations staff other jobs related to system administration. In a larger company, these may all be separate positions within a computer support or Information Services department. In a smaller group they may be shared by a few sysadmins, or a single person. A database administrator maintains a database system, is responsible for the integrity of the data and the efficiency and performance of the system. A network administrator maintains network infrastructure such as switches and routers, diagnoses problems with these or with the behavior of network-attached computers. A security administrator is a specialist in computer and network security, including the administration of security devices such as firewalls, as well as consulting on general security measures.
A web administrator maintains web server services that allow for internal or external access to web sites. Tasks include managing multiple sites, administering security, configuring necessary components and software. Responsibilities may include software change management. A computer operator performs routine maintenance and upkeep, such as changing backup tapes or replacing failed drives in a redundant array of independent disks; such tasks require physical presence in the room with the computer, while less skilled than sysadmin tasks, may require a similar level of trust, since the operator has access to sensitive data. Most employers require a bachelor's degree in a related field, such as computer science, information technology, electronics engineering, or computer engineering; some schools offer undergraduate degrees and graduate programs in system administration. In addition, because of the practical nature of system administration and the easy availability of open-source server software, many system administrators enter the field self-taught.
A prospective will be required to have some experience with the computer system they are expected to manage. In some cases, candidates are expected to possess industry certifications such as the Microsoft MCSA, MCSE, MCITP, Red Hat RHCE, Novell CNA, CNE, Cisco CCNA or CompTIA's A+ or Network+, Sun Certified SCNA, Linux Professional Institute, Linux Foundation Certified Engineer or Linux Foundation Certified System Administrator, among others. Sometimes exclusively in smaller sites, the role of system administrator may be given to a skilled user in addition to or in replacement of his or her duties; the subject matter of system administration includes computer systems and the ways people use them in an organization. This entails a knowledge of operating systems and applications, as well as hardware and software troubleshooting, but knowledge of the purposes for which people in the organization use the computers; the most important skill for a system administrator is problem solving—frequently under various sorts of constraints and stress.
The sysadmin is on call when a computer system goes down or malfunctions, must be able to and diagnose what is wrong and how best to fix it. They may need to have teamwork and communication skills. Sysadmins must understand the behavior of software in order to deploy it and to troubleshoot problems, know several programming languages used for scripting or automation of routine tasks. A typical sysadmin's role is not to design or write new application software but when they are responsible for automating system or application configuration with various configuration management tools, the lines somewhat blur. Depending on the sysadmin's role and skillset they may be expected to understand equivalent key/core concepts a software engineer understands; that said, system administrators are not software developers, in the job title sense. When dealing with Internet-facing or business-critical systems, a sysadmin must have a strong grasp of computer security; this includes not deploying software patches, but preventing break-ins and other security problems with preventive measures.
In some organizations, computer security administration is a separate role responsible for overall security and the upkeep of firewalls and intrusion detection systems, but all sysadmins are responsible for the security of computer systems. A system administrator's responsibilities might include: Analyzing system logs and identifying potential issues with computer systems. Applying operating system updates and configuration changes. Installing and configuring new hardware and software. Adding, removing, or updating user account information, resetting passwords, etc. Answering technical queries and assisting users. Responsibility for security. Responsibility for documenting the configuration of the system. Troubleshooting any reported problems. System performance tuning. Ensuring that the network infrastructure is up and running. Configuring and deleting file systems. Ensuring parity between dev and production environments. Training users Plan and manage the machine room environmentIn larger organizations, some of the tasks above may be divided amo