Ways to work with email. Modern methods of transmitting information
Information exchange and search tools information resources on the Internet.
| Parameter name | Meaning |
| Article topic: | Tools for exchanging information and searching for information resources on the Internet. |
| Rubric (thematic category) | Technologies |
Rice. 12. Mixed topology
Only in a network with a mesh topology there is a separate communication line to connect each pair of computers. In all other cases, the question inevitably arises of how to organize the sharing of communication lines by several computers on the network. As always when sharing resources, main goal This is a reduction in the cost of the network.
IN computer networks used as custom lines communications between computers, and shared ones, when one communication line is alternately used by several computers. In the case of using shared communication lines, a set of problems arises associated with their joint use, which includes both purely electrical problems of ensuring the required quality of signals when connecting several receivers and transmitters to the same wire, and logical problems of dividing access time these lines.
Exist various ways solving the organization's problem sharing to shared communication lines. Inside the computer there are problems with dividing communication lines between various modules also exist - an example is access to the system bus, which is controlled either by the processor or a special bus arbiter. In networks, the organization of shared access to communication lines has its own specifics due to the significantly longer time it takes for signals to propagate over long wires; moreover, this time should be different for different pairs of computers. Because of this, communication link access negotiation procedures can take an excessively long period of time and lead to significant losses in network performance.
Despite all these difficulties, in local networks shared communication lines are used very often. At the same time, in last years There has been a tendency to abandon shared data transmission media in local networks. This is due to the fact that the reduction in network cost achieved in this way comes at the cost of performance.
An important problem that needs to be taken into account when combining three or more computers is the problem of their addressing. There are several requirements for the network node address and its destination scheme.
The address must uniquely identify a computer on a network of any size.
The address must have a hierarchical structure, convenient for building large networks.
The address must be convenient for network users, which means that it must have a symbolic representation, for example, www.cisco.com.
Since all the listed requirements are difficult to combine within the framework of any one addressing scheme, in practice several schemes are usually used at once, so that the computer simultaneously has several address-names. Each address is used in the situation when the corresponding type of addressing is most convenient. And so that there is no confusion and the computer is always uniquely identified by its address, special auxiliary protocols are used that can determine addresses of other types using an address of one type.
The most widespread are two node addressing schemes.
Symbolic addresses or names. These addresses are intended to be remembered by people and therefore usually carry a semantic load. Symbolic addresses are easy to use in both small and large networks. To work in large networks a symbolic name can have a complex hierarchical structure. All individual pieces of information separated by a "." are called domains. For example, the email address of Minsk State Linguistic University has next view: mslu.unibel.bv. where mslu is the name of the university, unibel is the name of the provider to which the university server is connected, and by is the abbreviated name of the Republic of Belarus (Byelorussia).
Among the domains, there is a certain hierarchy. The domain at the end of the address is usually called a domain top level. It identifies the geographic region of the network, its type, or the type of organization to which the message is sent. Thus, in the USA, the last domain usually denotes the type of organization: commercial (.com), educational (.edu), government (.gov), etc.
Numeric compound addresses. Symbolic names are convenient for humans, but due to their variable format and potentially large length, they are not very economical to transmit over a network. For this reason, to work in large networks, numerical composite addresses of fixed and compact formats. Typical representatives of this type of address are IP address. IP address- This unique name, under which every computer connected to the Internet is known to all other computers on the World Wide Web. An IP address is usually written as a sequence of four regular decimal numbers, each of which is in the range from 0 to 255. When writing, numbers are separated from each other by dots. Eg, 147.120.3.28 or 255.255.255.255 - these are two IP addresses. Whenever a message is sent to any computer on the Internet, the IP address is used to indicate the address of the sender and recipient. For automatic conversion To transfer domain names of email addresses to the IP address of a computer on the Internet, a special program is used - DNS (Domain Names System).
Main areas of use Internet networks are: obtaining information and exchanging information. The means of information exchange include:
1. Email.
2. Teleconferences (newsgroups) and mailing lists.
3. File sharing.
4. Audio and video conferences.
5. Programs for communication and collaboration in real time.
6. Paging systems.
7. Internet telephony.
Information resource search tools:
1. Search engines.
2. Thematic catalogs.
3. Metasearch engines.
4. Accelerated search programs.
Email(e-mail or e-pistles) is a means of exchanging letters in in electronic format between people who have access to computer network. The basic concept of email is message. A message is usually understood as text transmitted over communication lines in a network from one user to another. The message can be considered an “electronic” version of a regular letter. An email message or letter consists of two parts: the header of the letter and the body of the letter. The header of the email contains the email addresses of the recipient and sender, its subject and the date it was sent.
To be able to send and receive messages by email, you need a so-called postal package. It usually includes following programs:
1. Mail server.
2. Transport program.
3. Mail client.
Mail server- a program that forwards messages from mailboxes to other servers or to the user’s computer at the request of his email client.
The mail server program manages the transmission of messages between clients and the Internet. If you are using a UNIX network operating system, then the UUCP (Unix-to-Unix Copy Protocol) program can serve as a mail server. UNIX systems). When using other network operating systems, the SMTP (Simple Mail) program is used as a mail server Transfer Protocol- mail transfer protocol). This system requires transport program . Such a program delivers messages to mail servers. They can be, for example, a POP (Post Office Protocol) server. mail center) or IMAP (Internet Mail Access Protocol) server. The mail server then delivers the message to the final recipient.
Mail client (mailer) – a program that helps you compose and send emails, receive and display letters on the user's computer.
The mail client provides the ability to read a received letter and write a response in offline mode, that is, without an Internet connection. There are quite a lot of email clients. Thus, for OS/2, Mac OS and UNIX operating systems, the Eudora mail program is used. For computers running Windows OS, email programs from Microsoft are widely used: MS OUTLOOK, INTERNET MAIL, EXCHANGE, OUTLOOK EXPRESS and Netscape MESSENGER. To transmit non-text information (audio and video files, multimedia data) by e-mail, the MIME (Multipurpose Internet Mail Extensions) standard is used.
Mailing list server is a program containing data about email addresses clients, answers to frequently asked questions, price lists, etc. Such a server analyzes messages received at its address and makes a decision on how and what to respond. If a message is received from a new client, the mailing list server automatically remembers his email address.
Operations with outgoing messages include:
· preparing a message;
· addressing;
· attaching files to messages;
· sending messages.
Operations with incoming messages include:
· notification of mail arrival;
· reading mail;
· preparing a response;
· redirection;
· organization of message storage or deletion.
Teleconferences (newsgroups) and mailing lists.
Teleconference (newsgroup) – a network forum organized for discussion and exchange of news on a specific topic. Most known system Teleconferencing is Usenet (User Network). Usenet a global, distributed discussion system that includes multiple newsgroups hosted on servers around the world.
Teleconferences Usenet News
also called newsgroups
(news groups). There are several tens of thousands of such groups. Each news group has its own name and hierarchical structure (a group may include several subgroups, each subgroup, in turn, may consist of other subgroups, etc.) For example, a news subgroup containing messages about WWW information systems is included in large group ʼʼ Computer Engineeringʼʼ and has the name comp.infosystems.www (ᴛ.ᴇ. group ʼʼComputer technologyʼʼ, subgroup ʼʼ Information Systemsʼʼ, subgroup ʼʼWWWʼʼ). The comp.infosystems.www subgroup includes 10 smaller subgroups: comp.infosystems.www.misk, comp.infosystems.www.users, comp.infosystems.www.providers, etc.
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There are newsgroups that discuss education (edu.), science (sci.), music (music.), etc. For example, fido.networks.bel-internet – a news group of the FidoNet network dedicated to discussion network problems(networks), in particular, Internet problems in Belarus (bel-internet).
Information stored in archives on newsgroup servers is the titles and descriptions of articles, but not the articles themselves. If desired, the user can also receive full articles.
In other words, newsgroups perform functions similar to mailing lists, but use specialized software and your protocol. There are several tens of thousands of newsgroups dedicated to various issues, from computer protocols to tourism. Messages directed to a newsgroup server are sent from it to all servers associated with it, on which of this message Not yet. On each server, the message is stored for a limited period of time, and therefore this Internet service has a news nature.
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The main purpose of using newsgroups is to be able to ask a question to many people at the same time and get an answer or helpful advice from a more experienced colleague.
Like any service on the Internet, teleconferencing uses client/server technology.
News server– a program that provides access to news groups hosted on this server. Example of a news server address news.unibel.by. There are special client programs for working with news servers.
Newsreader (client program for reading news)– a program that uses the NNTP protocol to transmit newsgroup messages from a news server.
An example is Outlook program Express included Internet Explorer, which, in addition postal protocols, also understands the NNTP news transfer protocol. Its rival colleague from the Netscape suite is the Netscape Collabra program.
There are teleconferences in which preliminary screening of messages that are not related to the topic of the conference is carried out. Such conferences are called moderated .
Moderated (managed) newsgroups – teleconferences in which all messages and replies are monitored moderator (managers) of this group who have the right to select articles.
In contrast, in unmoderated newsgroups, any message sent to the group is posted immediately.
Unmoderated (unmanaged) newsgroups are teleconferences in which anyone can post a message or reply to a message in that group.
To send a message to a particular newsgroup, mail client It is extremely important to fill out the standard positions:
1) name of the teleconference (Newsgroup);
2) topic (Subject);
3) area of distribution (Distribution);
4) keywords(Keywords);
5) abstract (Summary).
The essence of this service is essentially that information on some topic is received by a small (unlike Usenet News) circle of users who have subscribed to this list newsletters.
Mailing list topics vary widely, such as studying foreign languages, information Technology etc. Mailing lists can be controlled (moderated) or uncontrolled (unmoderated). Controlled lists have a manager (moderator), whose responsibilities include reading all letters coming to this list and filtering out unnecessary information(the so-called “noise”) and the formation of a selection of letters to be sent to subscribers. The mailing itself is carried out automatically by the mailing server. In unmoderated lists, all letters arriving at the list address are sent automatically. In controlled lists, subscription requires the permission of the moderator, and in uncontrolled lists it is carried out automatically.
Tools for exchanging information and searching for information resources on the Internet. - concept and types. Classification and features of the category "Means for exchanging information and searching for information resources on the Internet." 2017, 2018.
Today, courts often accept electronic correspondence as written evidence. However, for this she must have legal force. Meanwhile, clear and uniform rules and methods for determining the legitimacy of virtual correspondence have not yet been developed, which leads to a large number of problems.
Let's look at a few ways to make emails look legal force.
Long gone are the days when the only means of communication were letters written on paper. The development of economic relations between economic entities is no longer conceivable without the use of information technology. This is especially true when counterparties are located in different cities or even countries.
Communication via electronic communications helps reduce material costs, and also allows you to quickly develop a common position on specific issues.
However, such progress should not be considered only in terms of positive side. Various disputes often arise between subjects of economic relations; to resolve them, they turn to the courts. The court makes a decision based on an assessment of the evidence provided by the parties.
At the same time, the relevance, admissibility, reliability of each evidence separately, as well as the sufficiency and interconnection of the evidence in their totality are analyzed. This rule enshrined both in the Arbitration Procedure Code of the Russian Federation (clause 2 of Article 71) and in the Code of Civil Procedure of the Russian Federation (clause 3 of Article 67). In the process of determining the admissibility and reliability of the evidence provided, the court often asks questions, the solution of which significantly affects the outcome of the case.
Usage electronic document management in relations between economic entities is regulated by the norms of the Civil Code of the Russian Federation. In particular, in paragraph 2 of Art. 434 indicated: agreement in writing can be concluded by exchanging documents via electronic communication, which makes it possible to reliably establish that the document comes from a party to the contract.
In accordance with paragraph 1 of Art. 71 Code of Civil Procedure of the Russian Federation and paragraph 1 of Art. 75 of the Arbitration Procedure Code of the Russian Federation, written evidence is business correspondence containing information about circumstances relevant for the consideration and resolution of the case, executed in the form digital recording and received via electronic communication.
For use electronic documents In legal proceedings, two conditions must be met. Firstly, as already indicated, they must have legal force. Secondly, the document must be readable, that is, it must contain information that is generally understandable and accessible to perception.
This requirement stems from general rules legal proceedings, which presuppose the immediacy of judges’ perception of information from sources of evidence.
Often the court refuses to include it as evidence in the case materials. email correspondence, which does not meet the above conditions, and subsequently makes a decision that does not satisfy the legitimate requirements of the interested party.
Let's consider the main ways to legitimize electronic correspondence before and after the start of proceedings.
Working with a notary
If the proceedings have not yet begun, then to give electronic correspondence legal force, you need to involve a notary. In paragraph 1 of Art. 102 of the Fundamentals of Legislation on Notaries (Fundamentals) states that, at the request of interested parties, a notary provides evidence necessary in court or an administrative body if there are reasons to believe that the provision of evidence will subsequently become impossible or difficult. And in paragraph 1 of Art. 103 of the Fundamentals stipulates that in order to secure evidence, the notary inspects written and material evidence.
According to paragraph 2 of Art. 102 Fundamentally, a notary does not provide evidence in a case that, at the time interested parties contact him, is being processed by a court or administrative body. Otherwise, the courts recognize notarized electronic correspondence as inadmissible evidence (Resolution of the Ninth AAS dated March 11, 2010 No. 09AP-656/2010-GK).
It is worth recalling that, based on Part 4 of Art. 103 Fundamentals, provision of evidence without notifying one of the parties and interested parties is carried out only in urgent cases.
In order to examine the evidence, a protocol is drawn up, in which, in addition to detailed description The notary's actions must also contain information about the date and place of the inspection, the notary performing the inspection, the interested parties participating in it, and also list the circumstances discovered during the inspection. The emails themselves are printed and filed with a protocol, which is signed by the persons participating in the inspection, by a notary and sealed with his seal. By virtue of the Determination of the Supreme Arbitration Court of the Russian Federation dated April 23, 2010 No. VAS-4481/10, the notarial protocol for the inspection of an electronic mailbox is recognized as appropriate evidence.
Currently, not all notaries provide services for certification of emails, and their cost is quite high. For example: one of the notaries in Moscow charges 2 thousand rubles for one page of the descriptive part of the protocol.
A person interested in providing evidence applies to a notary with a corresponding application. It should indicate:
- evidence to be secured;
- the circumstances that are supported by this evidence;
- the grounds for which evidence is required;
- at the time of contacting a notary, the case is not being processed by a court of general jurisdiction, an arbitration court or an administrative body.
Notaries inspect the contents email box or remotely, that is, they use remote access to a mail server (this may be the server of a provider providing an electronic communications service under a contract; a mail server of a domain name registrar or a free Internet mail server), or directly from the computer of the interested party on which an e-mail program is installed ( Microsoft Outlook, Netscape Messenger, etc.).
During a remote inspection, in addition to the application, the notary may need permission from the domain name registrar or Internet provider. It all depends on who exactly supports the operation of mailboxes or an electronic mail server under the contract.
Certification from the provider
Resolutions of the Ninth AAS dated 04/06/2009 No. 09AP-3703/2009-AK, dated 04/27/2009 No. 09AP-5209/2009, FAS MO dated 05/13/2010 No. KG-A41/4138-10 stipulate that the courts also recognize the admissibility of electronic correspondence , if it is certified by the Internet service provider or domain name registrar who are responsible for managing the mail server.
The provider or domain name registrar certifies electronic correspondence at the request of an interested party only if it manages the mail server and such right is specified in the service agreement.
However, the volume of electronic correspondence can be quite large, which in turn can complicate the process of providing paper documents. In this regard, the court sometimes allows the provision of electronic correspondence on electronic media. Thus, the Arbitration Court of the Moscow Region, making a Decision dated August 1, 2008 in case No. A41-2326/08, referred to the admissibility of electronic correspondence provided to the court on four CDs.
But when considering the case in the appellate instance, the Tenth AAC, by its Resolution dated 10/09/2008 in case No. A41-2326/08, recognized the reference to electronic correspondence as unfounded and canceled the decision of the court of first instance, indicating that the interested party did not submit any documents provided for by the concluded parties agreement.
Thus, emails relating to the subject of the dispute must be submitted to the court in writing, and all other documents can be submitted on electronic media.
Confirming the contents of letters by referring to them in subsequent paper correspondence will help prove the facts stated in virtual correspondence. The use of other written evidence is reflected in the Resolution of the Ninth AAS dated December 20, 2010 No. 09AP-27221/2010-GK. Meanwhile, the court, when considering the case and assessing the evidence provided by the parties, has the right not to consider paper correspondence with links to electronic correspondence admissible.
He only takes it into account and makes a decision based on a comprehensive analysis of all the evidence presented.
Get help from an expert
If the proceedings have already begun, then to give electronic correspondence legal force it is necessary to exercise the right to attract an expert. In paragraph 1 of Art. 82 of the Arbitration Procedure Code of the Russian Federation stipulates that in order to clarify issues that arise during the consideration of a case that require special knowledge, the arbitration court appoints an examination at the request of a person participating in the case, or with the consent of the persons participating in it.
If the appointment of an examination is prescribed by law or a contract, or is required to verify an application for falsification of the evidence presented, or if an additional or repeated examination is necessary, the arbitration court may appoint an examination on its own initiative. The appointment of an examination for the purpose of verifying the evidence presented is also provided for in Art. 79 Code of Civil Procedure of the Russian Federation.
In the application for appointment forensics it is necessary to indicate the organization and specific experts who will carry it out, as well as the range of issues for which the interested party decided to apply to the court to order an examination. In addition, information about the cost, timing of such an examination should be provided and deposited with the court full amount to pay for it. The involved expert must meet the requirements established for him in Art. 13 of the Federal Law “On State Forensic Expert Activities in the Russian Federation”.
Attachment to the case materials as evidence of an expert's opinion on the authenticity of electronic correspondence is confirmed by judicial practice (Decision of the Moscow Arbitration Court dated 08/21/2009 in case No. A40-13210/09-110-153; Resolution of the Federal Antimonopoly Service of the Moscow Region dated 01/20/2010 No. KG-A40 /14271-09).
Based on the contract
In paragraph 3 of Art. 75 of the Arbitration Procedure Code of the Russian Federation notes that documents received via electronic communication are recognized as written evidence if this is specified in the agreement between the parties. Accordingly, it is necessary to indicate that the parties recognize the equal legal force of correspondence and documents received via fax, the Internet and other means as the originals. electronic methods communications. In this case, the contract must specify the email address from which electronic correspondence will be sent, and information about confidant authorized to conduct it.
The contract must stipulate that the designated email address is used by the parties not only for work correspondence, but also for the transfer of work results, which is confirmed by the position of the FAS MO in Resolution No. KG-A40/12090-08 dated January 12, 2009. The Decree of the Ninth AAS dated December 24, 2010 No. 09AP-31261/2010-GK emphasizes that the contract must stipulate the possibility of using e-mail for approval terms of reference and making claims regarding the quality of services provided and work performed.
In addition, the parties may provide in the agreement that notifications and messages sent by email are recognized by them, but must be additionally confirmed within a certain period by courier or by registered mail(Resolution of the Thirteenth AAS dated April 25, 2008 No. A56-42419/2007).
To summarize, we can say that today there is a practice of courts using electronic correspondence as written evidence. However, taking into account the requirements of procedural legislation regarding the admissibility and reliability of evidence, virtual correspondence is taken into account by the court only if it has legal force.
In this regard, a large number of problems arise, since a unified methodology for determining the legitimacy of electronic correspondence has not yet been formed. The right of an interested party to contact a notary in order to secure evidence is enshrined, but there is no regulatory act of the Ministry of Justice of the Russian Federation regulating the procedure for the provision of such services by notaries. As a result, there is no single approach to determining their value and forming a clear mechanism for implementing this right.
There are several ways to give electronic correspondence legal force in order to present it as evidence in court: securing electronic correspondence from a notary, certification from an Internet provider, by reference to emails in further paper correspondence, as well as confirmation of their authenticity by forensic examination.
A competent approach to the timely provision of electronic correspondence as written evidence will allow business entities to fully restore their violated rights when resolving disputes.
Over time, the methods of transmitting information have changed. It all started with oral speech. Sagas and legends were passed down from mouth to mouth, from which the history of peoples was formed. Then messengers rushed along the roads with letters. After many centuries, they turned into postmen, and telephone communication became firmly established in our lives. Today, paper letters are almost obsolete, and telephone communications will soon be completely replaced by the Internet. More and more people prefer to communicate and exchange information not by phone, but through Internet networks, because it is in them that the most quick ways transmission of information.
However, despite technological progress, a document remains one of the main ways to convey any information. Today, documents exist in both paper and electronic form. For exchange, new means of transmitting information are being developed every day. Here email takes first place. With its help, the addressee receives a letter almost instantly, no matter in any corner globe he was not there. E-mail is provided by mail servers that store thousands of mailboxes - so-called accounts. In addition to email, information is transmitted using ICQ, Skype and similar programs. There is a more convenient way of communication - Internet conferences. Telephone connection Internet conferences have not been replaced just because they require high speed communication with the World Wide Web.
The process of transferring information occurs either through computer networks or through electronic media such as CDs, Flash drives and removable SSD drives. have their own classification. They differ in territory coverage, topology and management method. Local networks have the smallest coverage area - in them the distance between nodes is only a few meters. Second place is taken corporate networks- they are available within the office or enterprise. The biggest are territorial networks, which, according to their scale, are divided into regional and global.
They are divided into three categories. In a bus network, computers are connected to one line, and information transmitted from one computer immediately becomes available to everyone else. IN ring network nodes follow each other. Information in it is transmitted in a one-way direction. The star network has a central control node, from which ray lines diverge to the other nodes.
There are two types of network management. In the client-server type, the network is managed by large servers, and the remaining computers are client computers and have no influence on the network. In the peer-to-peer type, all network nodes have absolutely equal rights. In them, each user decides for himself which folders or files will become available to everyone. Such networks are very poorly protected from hacking.
All possible methods of transmitting information have one scheme. It includes the sender of information, the transmission channel and the recipient of information. Channels differ in information transmission speed, which is measured in bits/s and its multiples. The World Wide Web is called servers, and those who use it are called consumers. Typically, the consumer enters through a fiber optic cable. However, in Lately come into use wireless methods Internet access that uses technologies such as Wi-Fi or Bluetooth. It is also impossible not to remember mobile networks, because more and more people are using mobile internet or 3G modems that use WAP or GPRS protocols.
So, methods of transmitting information replaced each other until the Internet was discovered. As new technologies develop, it will become increasingly accessible until it replaces all other means of communication.
Every person constantly encounters information, and so often that not everyone can explain the meaning of the concept itself. Information is information that is transmitted from one person to another using various means of communication.
There are various ways to transfer data, which will be discussed below.
How information is transmitted
In the process of human development, there is a constant improvement in the mechanisms by which information is transmitted. Methods for storing and transmitting information are quite varied, since there are several systems in which data is exchanged.
There are 3 directions in the data transmission system: transmission from person to person, from person to computer and from computer to computer.
- Initially, information is obtained through the senses - vision, hearing, smell, taste and touch. To transmit information over a short distance, there is a language that allows you to communicate the received information to another person. In addition, you can convey something to another person by writing a letter or during the performance, as well as when talking on the phone. Despite the fact that the last example uses a communication device, that is, an intermediate device, it allows information to be transmitted in direct contact.
- To transfer data from a person to a computer, it must be entered into the device’s memory. Information may have different type, which will be discussed further.
- Transfer from computer to computer occurs through intermediate devices (flash card, Internet, disk, etc.).
Data processing
After receiving necessary information there is a need for their storage and transmission. Methods of transmitting and processing information clearly represent the stages of human development.
- At the beginning of its development, data processing involved transferring it to paper using ink, pen, pen, etc. However, the disadvantage of this processing method was the unreliability of storage. If we mention methods of storing and transmitting information, storage on paper has a certain period, which is determined by the service life of the paper, as well as the conditions of its use.
- The next stage is mechanical information technology, which uses a typewriter, telephone, and voice recorder.
- Next to replace mechanical system Electrical processing of information has come, because methods of transmitting information are constantly being improved. Such means include electric typewriters, portable voice recorders, and copying machines.
Types of information
The types and methods of transmitting information differ depending on its content. This can be textual information presented orally and in writing, as well as symbolic, musical and graphic. TO modern species data also includes video information.
A person deals with each of these forms of information storage every day.
Means of information transmission
The means of transmitting information can be oral and written.
- Oral means include speeches, meetings, presentations, and reports. When using this method, you can count on a quick reaction from your opponent. The use of additional nonverbal means during a conversation can enhance the effect of speech. Such means include facial expressions and gestures. However, at the same time, information received orally does not have long-term effect.
- Written media are articles, reports, letters, notes, printouts, etc. In this case, one cannot count on a quick reaction from the public. However, the advantage is that the information received can be re-read, thereby assimilating the information.
Methods of presenting information
As you know, information can be presented in several forms, which, however, does not change its content. For example, a house can be represented as a word or a graphic representation.
Methods of presenting and transmitting information can be depicted in the following list:
- Text information. It allows you to provide the most complete information, but may contain a large amount of data, which contributes to its poor assimilation.
- A graphic image is a graph, diagram, diagram, histogram, cluster, etc. They allow you to briefly present information, establish logical connections, cause-and-effect relationships. In addition, information in graphical form allows you to find solutions to various issues.
- The presentation is a colorful, visual example of the way information is presented. It can combine both textual data and their graphical display, that is different kinds presentation of information.
Concept of communication
Communication is a system of interaction between several objects. In a generalized sense, this is the transfer of information from one object to another. Communication is the key to the success of an organization.
Methods of transmitting information (communication) perform the following functions: organizational, interactive, expressive, incentive, perceptual.
The organizational function provides a system of relationships between employees; interactive allows you to shape the mood of others; expressive colors the mood of others; incentive calls for action; perceptual allows different interlocutors to understand each other.
Modern methods of transmitting information
The most modern methods of transmitting information include the following.
The Internet contains a huge amount of information. This allows you to gain a lot of knowledge without bothering with studying books and other paper sources. However, in addition to this, it contains methods and means of transmitting information similar to historically older models. This is an analogue of traditional mail - electronic mail, or e-mail. The convenience of using this type of mail lies in the speed of letter transmission and the elimination of stages of delivery. Today, almost everyone has an email address, and communication with many organizations is maintained precisely through this method of transmitting information.
GSM digital standard cellular communication, which is widely used everywhere. In this case, spoken speech is encoded and transmitted through a converter to another subscriber. All necessary information located in a SIM card, which is inserted into mobile device. Availability today of this product communication is a necessity as a means of communication.
WAP allows you to view on the screen mobile phone web pages with information in any form: text, numeric, symbolic, graphic. The image on the screen can be adapted to the screen of a mobile phone or have a look similar to a computer image.
Methods of transmitting information modern type also include GPRS, which allows you to packet transmission data to your mobile device. Thanks to this communication tool, continuous use of packet data at the same time is possible big amount person at the same time. Among the properties of GPRS are high data transfer speeds, payment only for transmitted information, great possibilities of use, and compatibility parameters with other networks.
The Internet, through the use of a modem, allows you to obtain high speed information transfer at a low cost of such access. A large number of Internet providers creates a high level of competition between them.
Satellite communication allows you to access the Internet via satellite. The advantage of this method is its low cost, high speed data transmission, however, among the shortcomings there is a noticeable one - the dependence of the signal on weather conditions.
Possibility of using information transmission media
As new means of transmitting information emerge, opportunities for unconventional use arise. various devices. For example, the possibility of video conferencing and video calling gave rise to the idea of using optical devices in medicine. In this way, information about the pathological organ is obtained through direct observation during surgery. When using this method of obtaining information, there is no need to make a large incision; the operation can be performed with minimal damage to the skin.
Rice. 12. Mixed topology
Only in a network with a full mesh topology there is a separate communication line to connect each pair of computers. In all other cases, the question inevitably arises of how to organize the sharing of communication lines by several computers on the network. As always when sharing resources, the main goal here is to reduce the cost of the network.
Computer networks use both individual communication lines between computers and shared ones, when one communication line is alternately used by several computers. In the case of using shared communication lines, a complex of problems arises associated with their joint use, which includes both purely electrical problems of ensuring the required quality of signals when connecting several receivers and transmitters to the same wire, and logical problems of dividing access to these lines in time .
There are various ways to solve the problem of organizing shared access to shared communication lines. Inside a computer, problems of dividing communication lines between different modules also exist - an example is access to system bus, controlled either by the processor or a special bus arbiter. In networks, the organization of shared access to communication lines has its own specifics due to the significantly longer time it takes for signals to propagate over long wires; moreover, this time can be different for different pairs of computers. Because of this, link access negotiation procedures can take an excessive amount of time and lead to significant losses in network performance.
Despite all these difficulties, shared communication lines are used very often in local networks. However, in recent years there has been a tendency to abandon shared data transmission media in local networks. This is due to the fact that the reduction in network cost achieved in this way comes at the cost of performance.
An important problem that needs to be taken into account when connecting three or more computers is the problem of their addressing. There are several requirements for the network node address and its destination scheme.
The address must uniquely identify a computer on a network of any size.
The address must have a hierarchical structure, convenient for building large networks.
The address must be convenient for network users, which means that it must have a symbolic representation, for example, www.cisco.com.
Since all of the above requirements are difficult to combine within the framework of any one addressing scheme, in practice several schemes are usually used at once, so that the computer simultaneously has several address-names. Each address is used in the situation when the corresponding type of addressing is most convenient. And so that there is no confusion and the computer is always uniquely identified by its address, special auxiliary protocols are used that can determine addresses of other types using an address of one type.
The most widespread are two node addressing schemes.
Symbolic addresses or names. These addresses are designed to be remembered by people and therefore usually carry meaning. Symbolic addresses are easy to use in both small and large networks. To work in large networks, a symbolic name can have a complex hierarchical structure. All individual pieces of information separated by a "." are called domains. For example, the email address of the Minsk State Linguistic University is as follows: mslu.unibel.bv. where mslu is the name of the university, unibel is the name of the provider to which the university server is connected, and by is the abbreviated name of the Republic of Belarus (Byelorussia).
Among the domains, there is a certain hierarchy. The domain at the end of the address is called the top-level domain. It identifies the geographic region of the network, its type, or the type of organization to which the message is sent. Thus, in the USA, the last domain usually denotes the type of organization: commercial (.com), educational (.edu), government (.gov), etc.
Numeric compound addresses. Symbolic names are convenient for humans, but due to their variable format and potentially large length, they are not very economical to transmit over a network. Therefore, to work in large networks, numerical compound addresses of fixed and compact formats are used as node addresses. A typical representative of this type of address is an IP address. IP address is the unique name by which each computer connected to the Internet is known to all other computers on the Internet. worldwide network. An IP address is usually written as a sequence of four ordinary decimal numbers, each of which is in the range from 0 to 255. When writing, the numbers are separated from each other by dots. For example, 147.120.3.28 or 255.255.255.255 - these are two IP addresses. Whenever a message is sent to any computer on the Internet, the IP address is used to indicate the address of the sender and recipient. To automatically convert domain names of an email address into the IP address of a computer on the Internet, a special program is used - DNS (Domain Names System).
The main directions of using the Internet are: obtaining information and exchanging information. The means of information exchange include:
1. Email.
2. Teleconferences (newsgroups) and mailing lists.
3. File sharing.
4. Audio and video conferences.
5. Programs for communication and collaboration in real time.
6. Paging systems.
7. Internet telephony.
Information resource search tools:
1. Search engines.
2. Thematic catalogs.
3. Metasearch engines.
4. Accelerated search programs.
Email(e-mail or e-pistles) is a means of exchanging letters electronically between people with access to a computer network. The basic concept of email is message. A message is understood as text transmitted over communication lines in a network from one user to another. A message can be considered an “electronic” version of a regular letter. An email message or letter consists of two parts: the header of the letter and the body of the letter. The header of the email contains the email addresses of the recipient and sender, its subject and the date it was sent.
To be able to send and receive messages by email, you need a so-called mail package. Typically it includes the following programs:
1. Mail server.
2. Transport program.
3. Mail client.
Mail server– a program that forwards messages from mailboxes to other servers or to the user’s computer at the request of his mail client.
The mail server program manages the transmission of messages between clients and the Internet. If you are using a UNIX network operating system, then the UUCP (Unix-to-Unix Copy Protocol) program can serve as a mail server. When using other network operating systems, the SMTP (Simple Mail Transfer Protocol) program is used as a mail server. This system requires transport program . Such a program delivers messages to mail servers. They can be, for example, a POP (Post Office Protocol) server or an IMAP (Internet Mail Access Protocol) server. The mail server then delivers the message to the final recipient.
Mail client (mailer) – a program that helps to compose and send electronic messages, receive and display letters on the user’s computer.
The mail client provides the ability to read a received letter and write a response offline, that is, without connecting to the Internet. There are quite a lot of email clients. Thus, for OS/2, Mac OS and UNIX operating systems, the Eudora mail program is used. For computers running Windows OS, Microsoft email programs are widely used: MS OUTLOOK, INTERNET MAIL, EXCHANGE, OUTLOOK EXPRESS and Netscape NETSCAPE MESSENGER. To transmit non-text information (audio and video files, multimedia data) by e-mail, the MIME (Multipurpose Internet Mail Extensions) standard is used.
Mailing list server is a program containing data on customer email addresses, answers to the most frequently asked questions, price lists, etc. Such a server analyzes messages received at its address and makes a decision on how and what to respond. If a message arrives from a new client, the mailing list server automatically remembers the client's email address.
Operations with outgoing messages include:
· preparing a message;
· addressing;
· attaching files to messages;
· sending messages.
Operations with incoming messages include:
· notification of mail arrival;
· reading mail;
· preparing a response;
· redirection;
· organization of message storage or deletion.
Newsgroups (newsgroups) and mailing lists.
Teleconference (newsgroup) – an online forum organized for discussion and exchange of news on a specific topic. The most famous teleconferencing system is Usenet (User Network). Usenet global distributed system for discussion, including many newsgroups stored on servers around the world.
Teleconferences Usenet News also called newsgroups (news groups). There are several tens of thousands of such groups. Each news group has its own name and hierarchical structure (a group may include several subgroups, each subgroup, in turn, may consist of other subgroups, etc.) For example, a news subgroup containing messages about WWW information systems is included in a large group “Computer technology” and has the name comp.infosystems.www (i.e. group “Computer technology”, subgroup “Information systems”, subgroup “WWW”). The comp.infosystems.www subgroup includes 10 smaller subgroups: comp.infosystems.www.misk, comp.infosystems.www.users, comp.infosystems.www.providers, etc. There are news groups where education issues are discussed ( edu.), science (sci.), music (music.), etc. For example, fido.networks.bel-internet is a news group of the FidoNet network dedicated to discussing network problems (networks), in particular, Internet problems in Belarus (bel-internet).
Information stored in archives on newsgroup servers is the titles and descriptions of articles, but not the articles themselves. If desired, the user can also receive full articles.
Thus, newsgroups perform similar functions to mailing lists, but use specialized software and their own protocol to do so. There are several tens of thousands of newsgroups dedicated to various issues, from computer protocols to tourism. Messages sent to a newsgroup server are sent from it to all associated servers that do not already have the message. On each server, the message is stored for a limited period of time, so this Internet service has a news nature. The main purpose of using newsgroups is to be able to ask a question to many people at once and get an answer or useful advice from a more experienced colleague.
Like any service on the Internet, teleconferencing uses client/server technology.
News server– a program that provides access to news groups hosted on this server. Example of a news server address news.unibel.by. There are special client programs for working with news servers.
Newsreader (client program for reading news)– a program that uses the NNTP protocol to transmit newsgroup messages from a news server.
An example is the Outlook Express program from Internet Explorer, which, in addition to mail protocols, also understands the NNTP news transfer protocol. Its rival colleague from the Netscape suite is the Netscape Collabra program.
There are teleconferences in which preliminary screening of messages that are not related to the topic of the conference is carried out. Such conferences are called moderated .
Moderated (managed) newsgroups are teleconferences in which all messages and replies are monitored moderator (managers) of this group who have the right to select articles.
In contrast, in unmoderated newsgroups, any message sent to the group is posted immediately.
Unmoderated (unmanaged) newsgroups are newsgroups in which anyone can post or reply to a message in that group.
In order to send a message to a particular news group, you need to fill out the standard positions in your email client:
1) name of the teleconference (Newsgroup);
2) topic (Subject);
3) area of distribution (Distribution);
4) keywords (Keywords);
5) abstract (Summary).
The essence of this service is that information on a certain topic is received by a small (unlike Usenet News) circle of users who have subscribed to this mailing list.
The topics of mailing lists can be very diverse, for example, learning foreign languages, information technology, etc. Mailing lists can be controlled (moderated) or uncontrolled (unmoderated). Controlled lists have a manager (moderator), whose responsibilities include reading all letters coming to this list, filtering out unnecessary information (the so-called “noise”) and forming a selection of letters to send to subscribers. The mailing itself is carried out automatically by the mailing server. In unmoderated lists, all letters arriving at the list address are sent automatically. In controlled lists, subscription requires the permission of the moderator, and in uncontrolled lists it is carried out automatically.
