Free printable invitations

The protocols for the shipment of the e-mail are introduced and of articles of the newsgroup, comprised the format of the messages, the inclusion of encloses and multimediali documents to you, the use of the international alphabets and of as these acquaintances they can return useful to the sistemista in order to shape the systems, to the programmatore like introduction to the protocols, and the customer evoluto that it wants to deepen possibilit?RFC the 822: like you formatto the message Internet RFC 821: Smtp for the shipment of the mail As I not only intercept you the e-mail (and) In this second nose-dive we will occupy of two fundamental instruments of communication available in Internet: the e-mail and Vedremo that the two strategies of communication take advantage of a common format for the rappresentazione of the messages, and we will introduce. We will see also as it is possible to insert in the messages of the contents multimediali. many: we will only limit ourselves to one panoramic, heading for the understanding of the fundamental concepts and sending back to the bibliography for. Our fundamental instrument in order to lead the tests sar?il speech made in the previous nose-dive, trover?he this time the concepts is repeated and that therefore, to of new l?ei the protocols that will come introduced, the understanding effort would have to be smaller. the theory in order to only expose the indispensable elements and to pass endured to the examples and the experimentation on the authoritative and definitive field remains cited documents RFC, whose careful?ndispensabile reading for being able to realize real applications. RFC 822: like you formatto the message Dated Internet 1982, this RFC is proposed to put order between the myriad of forms you of existing messages to the time in the several nets and the several one. Reading to the RFC this?hiaramente percepibile effort from variet?elle the shapes in which the e-mail address could be expressed, cio?uello that for we today this format has the classic structure utente@dominio. had to be adaptable is to the e-mail, is to the other instruments of communication who went ourselves delineating. Therefore when I speak about email, article, or pi?enericamente about message, means always the same thing. of message they differ for via of the presence or less than determined information in the heading, but for the rest their structure. Once again, the pi?datta shape had to be chosen in order to represent the message, any was the net or the system that would have had to cross in its travel from the sender to. The choice fell, obviously, on a testuale format ASCII, conceived so that he was easy analyzable from part of the programs, but at the same time that he was also leggibile to the man. A message in the sense of RFC 822?unque a text composed from lines finished from the sequence of characters CR and LF, containing codes. Exotic alphabets and binary rows are, to this point of ours. The slid one you open them 2001?tato published RFC 2822 that frequently in the literature and?os?oto, than?iventato a species of "magical number", under to which all recognize the format of the Internet messages, a cos?mportante number that also the publisher has waited for to publish this document so that its number, 2822, my article parler?empre of RFC 822 recalled that one of its predecessore. perch?nche in this, also holding account of the modernizations and the precisazioni of the format of the Internet messages that are matured in nearly the 20 years. We see then as a typical message email is introduced:. Subject: King: I have ended the article for the PLUTO. Anch' I have ended the formattazione of the article: now me he seems that he joins po' in all browser well. The structure of the message acknowledges easy: the first lines are the heading, then there?na empty line, and therefore it follows the body of. The heading contains necessary the technical information for a sure field of heading constituted from the name of the field from the body of the field that extends until the end of the line. The body of some fields to pu?stendersi also on pi?ighe: the continuation lines must obligatorily begin with a space or with a code of tabulazione HT. in order to reconstruct the entire line it originates them, brace CR+LF of the previous line and the first character of spaziatura of the continuation line must be interprets to you from the programs like an only character of spaziatura. Viceversa, the bodies of the fields of the single heading in correspondence of the spaces can be broken. The line of separation between the heading and the body of the message must be empty, cio?on must contain characters but that. It would be enough a space, invisibile, in order to mark this line like continuation of the previous one, falsando the corrected interpretation of the heading of the message. The body of the message contains the message in prosa. 822 do not impose some particular limitation to the content of the body, n?er how much regard the number of lines, n?er how much. of 998 characters for line, but it recommends pi?i 78 excluded characters CR+LF in order not to favor the visualization under the various interfaces. The below general philosophy to the protocols defined in the following RFC?erci?a: you are permissive in ci?he your programs are in a position to being able to interpret, and you are. We return to the heading, and we describe the main fields that. RFC 822 says that these fields can appear written indifferently in capital letters or very small letters, however recommends that, when formatta a message, it comes respected the ortografia suggested in the document, and that also we will respect here. RFC 822 previews also a general mechanism in order to insert comments in prosa in the body of a heading field, comments that the software type of comment that appears pi?requentemente, and cio?l name just of the person associated to its address email. In the continuation, ovunque dir?he?ossibile to insert an address email, to pu?nserire one whichever of these solutions filler the address (or the addresses separates to you from virgole) of the sender (or the senders) of the message. a message comes written up to four hands, for which of usual addresses a field must here be appeared also the address of the effective sender of the message the address (or the addresses separate to you from virgole) of the adressee (or the adressees) of the message. the field copy-coal, that is "for information". field blind carbon copy (blind copy coal). The only difference?he this field never does not come transmitted with the message, for which the addresses in it contained uses legitimate and less legitimate do not appear than this instrument the auguries of good new year to all the customers, without that everyone can. to which we want are directed eventual answers to the message. Of norm the answers go addressed to the sender whose address to suggest varies uses profits of this possibilit?che happens inserting in the field. That correspondent happens putting a nonexistent address to us yours then gets angry, I enter not there. Draft of one is tightened that serveur smtp calculates typically being based on the name of dominion, the time and a number. This allows also to trace the movements of the message (as it records you of log the rows of the serveur) and to diagnose filler the ID of the message or the messages of which this message constitutes the retort filler the directory of the ID of the messages of which this message it constitutes the continuation, even if does not constitute one necessarily retort to all these. the programs client can reconstruct the correct tree of reading ("thread") and to introduce the messages in a structured shape that of?' object of the message, a reassumed species of that allows to identify it quickly in lists. Suggestion: to choose the object well favors the reading of the message from part of the adressee and its reperibilit?uccessiva: not to neglect never this fact if you want that your message comes read be ended to write, than often coincides with the given date of shipment lacks, serveur smtp affixes it automatically given comes on purpose from the program client of your computer, therefore one recommendation: the clock, the date and the jet lag one of your PC controlled well if you do not want to make the figure of the eternauti. the fields that they regularly begin with the characters, but of norm come ignore to you from the systems use in order to insert information, others still put us the pubblicit?altri try to insert the photography of the author of the message. This directory?olo one minimal part of fields that can appear explanations and references, finds itself in RFC 2076, than?a to hold to hand capacity the first times that are gone to curiosare in the headings. To generate an Internet message directly as text and respecting the corrected practical sintassi not?olto for the daily use, and not even?lla capacity of the less expert utilizzatori. Here perch?sistono vary programs for the management of the messaggistica Internet (email and newsgroup) that they guide the utilizzatore in the writing of the message. In the case of the graphical interfaces, typically it comes proposed a mask of input gi?uddivisa in fields, than the utilizzatore it must fill up. A schematic example could be that one of figure 1: Anch' I have ended the formattazione of the article: now me he seems that he joins po' in all browser well. Graphical interface for the writing of an Internet message. The utilizzatore compiles several the fields of input second necessit? to. of valid mail the single fields, and therefore formatta the second message. Obtained text ASCII, the message it comes finally sent using protocol smtp or NNTP, as we will describe in the next paragraphs. Often the e-mail programs preview also the possibilit?i to include some of the generally previewed fields of heading to level of the graphical interface do not allow to shape with a sure one libert?l layout of the mask of input, and allow to insert arbitrary fields still are limited to concur to add to the gi?ormattato message a sure text that the utilizzatore must supply. RFC 821: Smtp for the shipment of the mail In this RFC we once again meet our Jon Postel that in the 1982 (year much prolific one, evidently) explains us protocol smtp. "simple" I do not guarantee, above all in the light of the several reviews valid, and?o standard of base for protocol smtp. The scope of the protocol?uello to transport a message. This protocol comes used from ours client of mail in order to send it to serveur smtp of our ISP, and in its turn this serveur user?ncora smtp for recapitare the message. The protocol travels on TCP in testuale shape ASCII, and the interaction between the two computers happens in a similar way to that we have seen for protocol POP-3. The slid one you open them 2001?tato published RFC 2821, gi?atte for RFC 822, for which not previous me ripeter?alla, this new version is limited to consolidate, to dawn and to clear, but it does not add n?ambia some of funzionalit?ell' RFC 821, like precise the introduction of. Moreover, some of the funzionalit?reviste in the 821 are by now in disuse in the modern Internet, cos?ortando to. In order to make the experiments we will still use the telnet, this time on the door. As serveur we will be able to use our same machine, or we will be able to use the serveur SMTP of our ISP. Now that we know the structure of the messages. that happens in order to send the message of example seen in the previous paragraph. Of usual the messages come send you to an only address, but in this case I have intentional to render the things pi?nteressanti and, I hope, pi?struttive, sending the same message to two addresses:. 354 Start mail input. end with. Subject: King: I have ended the article for the PLUTO. Anch' I have ended the formattazione of the article: now me he seems that he joins po' in all browser well. Articulated protocol smtp?i?omplesso and of protocol POP-3, for which the serveur it always returns of the composed lines from a numerical code to three figures and from a description in prosa. numerical code it codifies happened or the failure of the commando sended from the client, and?d use and consumption of the programs. RFC 821 filler the complete directory of the their codes and of semantic. Poich?tiamo working interactively, we can limit to read the messages to us in prosa, that they are enough explicit. We see, in the order, several the commandos and examine of it the effect: The first commando that we use simply declares to the serveur the name of our computer, of norm he has pure informative scope, and in a generalized manner the serveur not even verification that features of a hostname. However, this name apparir?elle headings, for which?eglio avoiding to choose. The serveur answers to us simply with its name. declares our address of e-mail Here. the serveur makes its controls in order to verify that it is valid? this address that will come signals to you eventual disguidi taken place during the delivery, for which if we are interested to knowing that of?tato of our message?eglio to put here. The serveur reassures to us with its OK, and can go ahead. With this commando we inform the serveur of the address of. Also the serveur to pu?are its preventive verifications here on the indicated address other adressees, in the case we wanted to recapitare the same message to pi?ersone, as it happens in our example. This commando instructs the serveur that we are in order to transmit we will have to finish to the message writing one constituted line give. What not to pu?recisare in these famous telegraphic?he all the lines of the message that had to begin with a point, they will have to be made to precede from an other. Draft of the same convention used from serveur POP-3 that we have gi?isto, but this time applied to the contrary: we to having are to guarantee the respect of this rule. the e-mail programs will make equally. In our message of example not there are lines that begin with a point, for which we do not see in action this sagacity here. Completed the message, envoy the line of closing constituted from a single point, the serveur answers to us that the accepted?tato message. Siccome we do not have other to make in this connection, us she does not remain that to greet and to close the logon with a rispettoso QUIT. In the moments succeeded to you, responsible serveur smtp preoccuper?i to identify the serveur of the management of the mailbox of the adressees, them contatter?no to and tenter?Se, for one any reason, the transmission was not possible, the serveur ripeter?ltri tried you at a distance of time, notifying periodically to the sender the eventual problems finds to you. of all the tried ones to you, that they can continue also for some days in dependency of the configuration of the serveur, if still the message had not been recapitato with succeeding or pi?ei adressees, the serveur notificher?l sender the outcome negative of the operations and the motivation of such failure (remote serveur down. does not know you, but I find a something to us of moving in I hurry with which they work serveur smtp. ?n service to lowland velocit?a that it demands a high one affidabilit?per which deserves much attention. Banal suggestion: in order to make other experiments it convene to shape a serveur smtp on just the computer (. being sended the mail to s?tessi: sembrer?trano, but the cycle of shipment (smtp) and download (POP-3) of the message exercises all protocols of e-mail that we have seen, without need to send messages of test to right and to it lacks. Suggestion for the utilizzatori of Windows: as we have said slid nose-dive, client the telnet included with the operating system the interaction of the example?na frustrating experience, to perch?procurarsi PuTTY or Teraterm in substitution of this telnet. Some considerations before closing this express overflight on. With this term the information given to serveur smtp are indicated before sending the message, and cio?li addresses of the sender and the adressees, exactly the information that we find also in the cartacee envelopes for the mail. The addresses of the envelope are the only information on which the serveur it is based for recapitare the message: in effects, the serveur ignores the same content of the message and. An other important consideration?he norm serveur smtp?n degree to optimize the shipment of the mail to several addresses email residents in the same serveur: in these cases the serveur transmits to its serveur colleague one single copy of the message, specifying in the envelope. The remote serveur then supplies to duplicate the message in the several ones mailbox of the own customers. ?he through intasatissime the freeways of the information the?ransitato message a single time for all these customers. Therefore, as an example, if between the adressees appears copy of the message, specifying in the envelope the two addresses message with one hundred addresses rather than one hundred equal messages to. Last curiosit?supponiamo of wanting to send a very determined message email, but typically sar?olo the dominion of second level under which several are recorded blots some. serveur smtp to characterize its serveur colleague problem comes resolved to level of serveur DNS: ours I trust serveur smtp it interrogates several serveur DNS and it collects the relative information these information apparir?nche the indication of predisposed serveur smtp to receive all the mail for that dominion. We do not deepen the argument ulteriorly, but I hope that pack-saddles in order to render the idea of as the prodigio is come true. As I intercept to you the e-mail (and) not only Exists varies agencies that are taken care of systematic interceptions of the communications that happen via Internet, telephone, via fax. Between these remember Echelon (USA, Great Britain, New Zeland, Australia, Canada), Enfopol (Europe), SORM (Russia), SCS (NSA+CIA), ASIO (Australia), "Franchelon" (France), BND (Germany), and others that now do not come to me pi?isparate: black box in it centers them telephone, futuribili antennas radio, satellites and other systems and super secrets. It seems that they can also automatically analyze the spoken one in the normal telephone conversations from fixed apparatus and cellular telephone, concurring therefore the digitalizzazione and the successive crossing of. Between it seems and one says, seems that the systems of surveillance via satellite are so precise from being able to identify the movements of one person to the ground: sorridere, I pray. Reasonably, we can imagine that these getlteman execute also systematic scansions of the WEB, sicch?on this article we have guaranteed also we a good positioning in their system automatic rifle. Of sure I waited for to me that the systems employ to you can be so sophisticated or so banal that we do not imagine ourselves: the realt?pesso?i?orprendente of the fantasy. Sure information exist that some of these organisms have operated not only for reasons of legitimate defense and prevention, but that they have been employ to you also in political within and economic in order to favor it determines to you. E' easy to intuire the distortions that they can some follow to the libert?emocratiche, to the right to the privacy, but also to the economic laws and the principles of the competition this topic, perch?ui we will only take care ourselves of the technical aspects. The problem of the interception of the mail serious?bbastanza: protocols POP-3 and smtp we have inasmuch as they transmit in luminosity all the messages, that they are perci?acilmente intercepable is at the moment of the shipment (via smtp) is at the moment of the reception (via POP-3). The only practical solution that at the moment I feel myself to suggest?uella to make use massive of the techniques of crttazione to asymmetric key, so that the message is intelleggibile exclusively to the inside of the computer of who sendes it and of who it receives it. In such sense various programs available for the systems exist simil-Unix, GNU/Linux and Windows. beyond that the interface to commando line is previewed also graphical interfaces for several atmospheres and integration with some programs of several?isponibile for systems operated to you with the interface to commando line. that turns out me the graphical interface is available single. In favorably future the e-mail programs they will be equips you of a better integration with the crittazione system and digital company them, reducing the below technology to little easy usable buttons. Only the diffuse employment of these technologies to pu?istabilire an just equilibrium between the right to the confidentiality of the citizens, and necessit?egli the enquirers of being able to inquire and to pursue the crimes. Unfortunately this system not?erfetto: the crittazione comes only executed on the body of the message, while it continues to remain in luminosity the heading and therefore the sender and the adressee. The topic as soon as grazed in this extreme paragraph?i attualit?posso to suggest the readings suggested in bibliography. Up to now we have used exclusively with of characters ASCII in order codifying our witnesses, leaving in suspended the problem of the alphabets. The solution to this problem has found two roads: before via bit of codes ASCII takes advantage of the extension to 8, the second one via must instead extend the rappresentazione of the characters using a greater number. Standard ISO 8859 defines varies insiemi of characters (in usual characters ASCII, while the successes to you 128 codes come use you in order to codify vary devout characters? less exotic, to second of. Between the charset defined from this standard the western languages are comprised all, the cirillico, the Greek, the Hebrew and the Arab. charset the ISO-8859-1 comprises the languages Italian, French, Spanish and German, cos?oddisfacendo great part of the requirements be added the ISO-8859-15 that it includes the symbol of the Euro, the new. But attention: the public ISO only the correspondence between the binary code of the byte and the description of the character who it represents for effectively being able to visualize the characters must procurarsi respects to you font consistent to these standards. This standard has the advantage to demand minimums changes to the hardware and the software of the computers, perch?i draft only of the definition of charset the extensive ASCII about which we have spoken. Unfortunately they turn out excluded the systems of writing like the Chinese, than with its migliaia of symbols it could not never be in a single byte, and moreover two various alphabets cannot be stirred in the same text, as an example the Latin and the cirillico. A pi?enerale solution to the limitations that we have seen necessarily demands to use a greater number of bit in order to codify standard UCS (Universal Character Set) defined from standard ISO 10464. The 31 UCS uses one codifies to bit for character and comprises all the charset of the world, included Greek, Hebrew, cirillico, Arab. Is in course the jobs in order to include charset. In realt?l moment the first only 16 bit of the UCS are use you, for which?tata defined one implementazione. The Unicode, defined from the Unicode Consortium (. a implementazione of the UCS that uses this solution to 16 bit, and?tata adopted, as an example, in the systems operated you of Microsoft. Perhaps profit returns perch?i to attualit?edere as the Euro symbol comes codified in several the systems: - Here as it visualizes it yours browser: €. In the Unix atmosphere and similari, included software GNU, byte for character usually comes implemented codifies it UTF-8 of the Unicode. variable length from one to three. characters ASCII are represent to you with a byte in the usual way, while when "is ignited" the eighth active bit codifies it fine-byte (explained a lot to spanne, but to maintain compatibilit?on to the greater part of the bookcases of manipulation of stringhe, that they were conceived for the use with 8 characters of bit, and the preservant also the alphabetical ordering. Documentation GNU of the bookcase standard supplies ulterior details for the programmatore that it wants to totally integrate this implementazione of the Unicode in its programs. Protocol smtp and the systems of shunting of the e-mail only guarantee the support for messages codify to you in ASCII, and therefore. The UTF-8, that bit for byte?datto for the rappresentazione of the witnesses in the memory of the computers uses 8, but not. RFC 2152 defines therefore the UTF-7, a particular one codifies of the Unicode that takes advantage of exclusively codes ASCII: the character precedes codifies it "modified Base64" of the Unicode code to 16 bit. Draft of one little efficient from the point of view of the memorization and elaboration, but highly compatible solution with all. Exceeded the scoglio of the rappresentazione of the several international alphabets, it remains opened the problem of the shipment of binary rows. We remember once again that rows binary, like an image, contain all the phantom of possible values for the byte that compose it, sicch?on pu?erto to be transmitted via smtp or POP-3 without to interfere with disastrously with the solos being defined an algorithm in a position to executing in reversible way. In order pu?riginariamente to insert rows binary in the body of a message to equipment of system UUCP. Here we will say only that the program codifies three groups of byte in groups of 4 chosen characters ASCII between a sottoinsieme of 64 stampabili characters ASCII, and moreover adds to the permissions of the rows and the name of the rows same. This brano of text, inserted in the body of a message, crosses undamaged whichever system and protocol that ASCII supports, and usually comes recognized in way automatic rifle from the programs client of e-mail, and introduced as attached it must extract from the message the lines that go widely dal. recognized to the problem of the insertion of binary rows. Base-64?n other binary system of conversion from rows to USA one technical similar to in order codifying binary rows for the use with MIME. 3 byte come codify to you in groups of 4 characters ASCII, increasing codified in this way the chosen character set would appear cos?62YoW81QNptBYDXD//8MR9wZrl5nuBLOcD0cxAaK7JZimF3FsNqKYXM9kA0A ASCII for codifies it?uanto of pi?nnocuo and conservativo can be imagined: capital and very small letters, figures, the point and the slash /, for a total of 64 symbols. realize also this codify using. The client of mail not to pu?iconoscere this code automatically perch? indistinguishable from the normal text of the single message with opportune headings MIME it becomes useful, as we will see. The adhesive of all the solutions of rappresentazione seen end. This format of rappresentazione of the messages allows to exceed many limitations of format RFC 822, also remaining with absolutely compatible it (the authors uses "the orthogonal" word). what it allows to make MIME: to use charset alternated you to the ASCII for the heading of the message to insert or pi?ezioni in the body of the message, binary witnesses or rows are they, so that they are univocamente recognizable to describe the structured nature of the body of the message, distinguishing between attached sections correlated of a document and to support the 8 transmission to concurred bit l?ove. The documentation of voluminosa and complex format MIME?iuttosto, and is articulated in five main documents that go from the RFC. In this article I try to synthetize of only the main concepts through some examples are fine to s?tessi, but they can be used in concrete applications, without having to study this format in all the details. Often understood to the sistemista and the programmatore of having to generate email in way automatic rifle, as an example in order to signal to a customer or a customer information statistics of the accesses to its situated WEB, or for segnalargli the overcoming of the quota for its mailbox. a pi?legante result we could inviargli a document HTML. Subject: Overcoming WARNING quota disc. Yours mailbox it has exceeded the maximum dimension before possible to empty it, otherwise for technical reasons we will be forced to cancel all. For greater information on the conditions of. I have evidenced in grassetto the two lines key of all the mechanism:. it indicates that the message?n formed MIME version 1, body of the message?i type text and sottotipo. Siccome we have not specified various, the message is considered codified to 7 bit using. Once written the message in text rows, in order to send it enough. To send to a message with one image. Using several types MIME it records, we will be able to send also other types to you of information, as an example our usual figure:. Subject: One beautiful little figure for you 62YoW81QNptBYDXD//8MR9wZrl5nuBLOcD0cxAaK7JZimF3FsNqKYXM9kA0A. Like?acile to imagine, they exist also. ?na novit?dichiara that the data are it codifies in Base64. to find in circulation this type to you of messages after asserting itself of the client. for default with option MIME (the other possibilit?i seems that it is the uuencode), and in this case the formatta program all the messages with to the base of this following type MIME?l: all the client of mail do not have same possibilit?i the visualization some are in a position to showing a document HTML, others can show. The format to pi?arti alternatives allows to insert the same content in pi?orme various, leaving client the possibilit?i to choose the preferred format between those available ones. As example ripropongo the notification email exausted space that before we had. Here we will write it also like text ASCII:. Subject: Overcoming WARNING quota disc This e' a message in piu' parts alternatives these lines, means that yours client of mail it does not support. Cio' e' a good, thus you can see as they work. Yours maibox it has exceeded the concurred maximum dimension. Please, you supply before possible to empty it, otherwise for technical reasons we will be forced to cancel on the conditions of the service, you read the contract. Yours mailbox it has exceeded the maximum dimension before possible to empty it, otherwise for technical reasons we will be forced to cancel all. For greater information on the conditions of. The same content of the message comes therefore represented in. When the utilizzatore writes up a message does not notice of the double rappresentazione, but it is limited to use the funzionalit?ese available from the interface that comes to it. At the moment of the shipment, the program produces to shape HTML and the shape text of the same message. In my example the two witnesses are not perfectly equivalents: the link ipertestuale in this case he must various be reproduced, and in the shape text I have reproduced the URL for entire within to the parentheses. We describe to step step as this parameter works serves to declare tightens it of separation of the several parts that constitute the body of the message must be univoca, and in order to avoid collisions the programs stretch to render it much long and with one random sequence of figures, letters and. However in order to favor the leggibilit?ui I have chosen. - the body of the message begins with the text ". preamble?onsentito from detailed lists MIME, but second the same detailed lists, if present, must be ignored from the consistent programs to the MIME and therefore it does not have to be introduced to utilizzatore. the this possibilit?er to add an warning that sar?eggibile to those who they do not decide of a client with support MIME, that cos?otranno to understand the reason of (for they) the strange one. - Every section MIME in the body begins with the line of separation, constructed with two signs - (less) you follow yourself from tightens of boundary that I have specified in the heading heading MIME that declares the type of the data of this section, an empty line, and therefore the same data of the section where the successive line of separation appears. - To the term of the message it must less insert the line of separation continuation from others two signs ``-'' (). The pi?nteressante thing?he every section MIME in the body of the message assumes the same shape of a message, with its heading. In effects MIME concurs ricorsive declarations: every section to pu?ssere of the type multileaves and to contain therefore an other. This problem I leave it the reader for exercise, than to have the answer without to go. (Suggestion: it uses the method experiences them: it sendes to same you a message in format MIME with attached, and examines the result). C$r-with regard to the use of font alternated to you in the heading, the MIME concurs the use of several charset, included ISO and UTF-8: characters ASCII will not have to be wrapped within to one particular sequence of characters like in. Because of the presence of the accented letter "à", than not ago part of charset the ASCII, the client of mail has codified the object of the message specifying charset the ISO-8859-1, it has encircled the word in issue with a series of strange characters, and therefore it is codifying the accented letter with its esadecimale value. E' possible also to use charset a ASCII in the body of the message not being introduced an appropriate parameter in the field of ContentType heading: text/plain. charset="ISO-8859-1" With these last telegraphic annotations I close the speech on. Memory only that the same format comes used also from protocol HTTP for the WEB: in that case the channel?empre. Dated 1986, this RFC describes to the protocol Network News Transfer Protocol, a system distributed for the exchange of. These names are structured, and have a shape of the dealt type: Italy, computer, operating system, linux, to begin group contain several the messages, sayings articles, that they have a heading forgiveness of meant and, if present, they come ignores to you from while new fields of heading are introduced in order to half hold account of new (RFC 1036). heading the name of the group conserves theirs meant like for the email filler where the message. They can be indicated also pi?ruppi separates to you from one virgola (cross-post): in such case typically the newsserver he maintains a single copy of the message, optimizing the space disc filler the directory of the groups where they desire comes brought back the eventual answers to this article, in case this directory differs from that specifying in the directory of indicates that the answers must be sended via email to the sender, deductible from the field. if present, filler the date beyond which one desires that the article comes removed from the newsserver. the newsserver they clean up their memory to cadences decided in phase of configuration (from some days to several months). filler the directory of the ID of articles of which this article constitutes the continuation, and allows the programs client to order the reading trees. the body of this field transports messages of "technical" nature for the management of the newsserver, and of norm it does not have to be used from the normal school utilizzatore. in the groups moderates to you, filler address email of the moderator that has filtered this article the articles mail to you on a newsserver does not appear immediately, but come preventively forwards you via email to the moderator. The protocol of communication between a?i?rticolato program client and a newsserver of the smtp, but once again the interaction happens through an exchange of commandos expressed in testuale shape, riproducibili. We see the commandos main that we will use in the examples: The specific ID demands to the serveur the having message or having. The serveur distinguishes two shapes perch?' ID?n code comprised between the parentheses angle irons, while absolute between the several serveur, while in the second one form the number assigned to the article has meant local to the interrogated serveur. It instructs the serveur that of hour in then we are interested to interrogate the collection of present articles in the group group way the protocol saves to the client of having to specify the group for every given commando, reducing the traffic in net. This commando returns the directory of all the groups. Once finished the directory, the serveur returns a containing line a single point, in the respect of a tradition that us would have by now to be familiar. of migliaia of groups, we can wait for a directory to us indeed along group comes brought back in one line in the following shape:. Poich?l volume of traffic generated from this high commando?iuttosto, the programs client the invocano only to the first connection with the serveur, and therefore memorizzano locally in in order obtaining the directory of the new groups eventually were made available on the serveur, and aggiorner?quello that the program extension to the utilizzatore when these wishes subscription does not involve some formal action: draft simply to instruct the program on which is the groups to unload to the next one. The directory of the groups created after the date returns and the hour specifies to you. To notice that the two figures of the year go specific only last, for which 86 means 1986, 02 mean 2002. What succeder?al 2050 in then at moment not?protocollo smtp, this commando precedes the shipment of our article towards. The article must second be formattato the conventions that we have seen, the lines that they had to begin with a point must be made to precede from an other point in order to avoid ambiguit?e to the term of the article must send a line that contains a single point (per?che originaloni these editors of RFC. It commands to the serveur to close logon TCP. We have inasmuch as?acilmente sfruttabile protocol POP-3 also via telnet, and returns profit in some occasions. With the NNTP, instead, we touch the apex of the masochismo, and the divertimento. Here the exercise that we will make: 1) we will write an article, 2) we will insert it in the appropriate group for the tests. 3) we will go it rileggere, 4) and therefore we will cancel it with a message. We will still use ours I trust telnet but, for the occasion, to the dump of the screen alterner? my comments in prosa. Subject: Stormy night was one buia and. Well, telnet ce we have it, the message ce we have it, the instructions for the use also, therefore we connect the belts and we leave:. 200 Free Welcome to - Infostrada news serveur (Twister v1. Before sending the article I have intentional to control po' a situation, so as to to be able to then confront it after. of numbers: 211?l code of state, 36298?l present article number in the group, 2?l number of the first article while. We hold in mind this number well, perch? instructive to confront it with the number that the serveur attribuir?l message that we are in order to mail:. Subject: Stormy night was one buia and. To notice that I have put 4 points of ellipses, this message to appear? all those who will go to read to the group or the groups l?pecificati. endured to see if?tato the message truly digested:. Now the last article of the group?l number 37004: we bet. Subject: Stormy night was one buia and. NNTP-Posting-Date: Yours, 08 Jan 2002 19:54:21 MET. Well, all like previewed: the?isponibile article to the reading of. Spiace, now, to have to cancel this pearl of wisdom, but dovr?arlo in order to hold faith to the didactic engagement that me is. I take famous of the ID that has attributed the serveur to me. Subject: Stormy night was one buia and. The body of the message I have omitted it: what it counts they are the field. ET voil?l' article was and now not there?i?al its. - In my examples the article as soon as postato it turns out immediately. Not always the things are cos?Innanzitutto some groups are moderate to you, the ch?ignifica that our article not apparir?intanto that the moderator, typically a human, not avr?rovveduto to. This eventualit?a desume from the answer to, where we have seen appears also a flag that. - Moreover, some newsserver collect articles mail to you, but they integrate them in their date single base in according to time, even after a delay that to pu?ndare from little second ones to some tiny not?revedibile delay, but varies from system to system that the newsgroup is not one chat-linens. - Some programs client for the newsgroup expect to find again the article as soon as postato within little second ones, so as to to gain message the ID that the serveur has assigned to this message the ID it comes then memorizzato from the program for its for internal use only one funzionalit?vanzata a lot interesting, but that to pu?vere some contraindications: if the program does not find the message as soon as postato within the previewed maximum time, a problem presumes. - the use of the newsgroup involves addressing to immense and heterogenous platee even much of persons, for which the rigorous respect of the netiquette and the common rules of civilt?ono indispensable requirement. The arguments exposed in these two articles are truly many, and to want to explore them to bottom probably would demand study months conclusion of this introduction to the main protocols of Internet hopes of to have provoked in the reader, beyond to the normal hard work and trouble of the study, also some idea and some suggestione.ma?uccesso something that is not understood nothing to us, and has not worked. - I have read all, but just all, this article and also the previous one. - I have tried all the examples of interaction with telnet. [ I have thought It ] [ I have not thought it ] [ But insomma, cos'?sto telnet. - You express, with words yours, the pregi of this work. - You express, with words yours, the defects of this pocket calculating work and proceed cos?somma the relative scores you to the affirmative answers, embezzle the negative answers, multiplies per.14 and you extract the square root, you add a number and, if negative, indicates 0. to this point it ignores the result that you have obtained. With this according to article concludes the minium-series dedicated to i. I do not hide that the argument that I have dealt?olto immense and complex, for which I am not deceived of to have been exaustive, n?antomeno infallible perch?o gi?redisposto a page WEB to the address where to accommodate the unavoidable corrections and integrations that. Obviously, draft of one vile maneuver. Me it does not remain that to augur me of to have been useful to someone, and I invite to reflect on how much has been productive in the general interest. Situated official where they come publishes to you and archiviati documents RFC. RFC 854 - Detailed lists of protocol telnet. RFC 977 - Detailed lists of protocol NNTP. RFC 1036 - Standard for interchange of USENET messages. RFC 1216 - Protocol ULS (ultra-low speed) and Placed Italian. RFC 1641 - Using Unicode with MIME. RFC 1700 - Numbers assign to protocols IP and to the doors TCP, directory of types MIME and the charset it records to you. RFC 1939 - Detailed lists of protocol POP-3. RFC 2026 - The Internet standards process. RFC 2045, 2046, 2047, 2048, 2049 - Specific of format MIME. RFC 2076 - Directory of the fields of heading of the Internet messages, with description and references. RFC 2152 - UTF-7 - To mail-safe transformation format of Unicode. RFC 2279 - UTF-8, to transformation format of Unicode and ISO 10646. RFC 2821 - Detailed lists of protocol smtp (former RFC 821). RFC 2822 - Detailed lists of format for the messages Internet (former RFC 822). RFC 3160 - The Tao of IETF - To Novice' s Guides to the Internet Engineering. Various authors, Secrets spies codes number - Cryptography to you: the legal history, techniques, aspects, And RSA Laboratories, RSA Laboratories Frequently Asked Questions About Today' s Cryptography, Version 4, written its first program in 1981: a powerful cycle FOR printed on. Struck by lightning from this happening, from then does not have pi?messo of seviziare computer in the software and the hardware, and of these practical of it it has made its job and its hobby. discovers to Internet and the world of the nets data transmissions.