• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The Post Office Protocol (POP)

Extracts from this document...

Introduction

��ࡱ�>�� 9;����8�������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������5@ ��0�*bjbj�2�2 (>�X�X �������������������8 <��v\\\\\\\\$Ra�>�\\\\\>��\\S���\�\�\�\������\P rE�]���\d�i0�� � ������� �� \\�\\\\\>>�Introduction The Post Office Protocol (POP) was first issued on October 1984. The protocol suggests a simple method for workstations to access mail from a mailbox server. The protocol is dependent upon TCP (Transfer Control Protocol) and assumes that mail is posted by SMTP. POP in more detail, is a way for a server machine to store and serve mail for various client machines that are not connected to the Internet 24 hours a day. This makes it like an electronic Post Office Box, where your email is held in the POP server until you login and retrieve it. For example, if somebody sends you e-mail it usually cannot be delivered directly to your computer unless it is permanently connected to the Internet and has its own mail delivery system. The messages have to be stored somewhere. An Internet Service Provider is on-line 24 hours on 7 days of the week and can do that job. This is where the message will stay until either you retrieve it or the Internet Service Provider administrator (ISP) finds a pile of large storage files from messages. The ISP then deletes them because you have gone past your limit of space available for incoming messages and cannot receive any more. ...read more.

Middle

1. The Authorisation Stage (This how POP3 handles Authentication) Once the client has opened the TCP connection and the server has issued a greeting message starting with a positive response (+OK). Then the client has two possibilities. Either sending a user name and a password by USER and PASS commands or sending an encrypted password by the APOP command, as PASS does not hide the password on the screen. After verifying the identity of the client, the server acquires an exclusive access lock on the mail drop. If the lock isn't acquired the server responds with a negative status and may close the connection or stay in the authorisation stage in order to allow issuing new authentication commands. After the lock is acquired the server assigns each message, a message number starting with 1. 2. The Transaction Stage After the client has successfully identified itself to the server, the server enters the transaction stage. Tthe client may issue commands and get responses from the server to each command. When the client issues a QUIT command the server enters the Update stage. Some Commands in the Transaction Stage � STAT � How many messages in the mailbox. � LIST [msg] � List a particular message. ...read more.

Conclusion

This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ 7h((o(p(�(�(S)T)�)�)7*8*�*�*�*�*�������������h"h"OJQJh"h"CJOJQJ%h"h"OJQJfHq� ����)h"h"CJOJQJfHq� ����h"h=ih"h"mHsH h=ih" �� 6 7 8 9 | } ~ � � � � � � � � � � � �����������������������������gd=i(�*��� � ����opqr����HIVWXY1234�����������������������������������gd=i�������������UVWX��������-./�����������������������������gd=i/0[\������67efgh�������������������������������������������gd=i�����������q!r!s!t!�!�!�!�!S#T#U#V#�$�$�$�$�&�&�&�����������������������������gd=i�&�&�'�'((p(q(r(s(�(�(�(�(T)U)V)W)�)�)�)�)8*9*:*;*�*��������������������������$a$gd"$a$gd"gd=i�*�*�*�*�*�*�����gd=i&1�h:p=i��/ ��=!�'"�'#��$��%��D@�D NormalCJ_H aJmH nHsH tHDA@�D Default Paragraph FontRi�R Table Normal�4� l4�a� (k�(No ListDZ@�D =i Plain TextCJOJQJ^JaJ4@4 "Header ���!4 @4 "Footer ���!`�o"` "watermark header$a$CJOJQJfHq� ����N�o2N "watermark footer$a$ CJOJQJ�">�������"r�V�:���*� �/��&�*�*�*7h q s � � U!W!�!�!9";"�"�"h �" �"��alex�"=i�@ @���"P@��Unknown������������G��z ��Times New Roman5V��Symbol3&� �z ��Arial7&�� �VerdanaG5�� �����h�MS Mincho-�3� fg?5� �z ��Courier New"1���h�J�f�J�f�J�f��1���1�\�������4d d 3�� H�?������������������=i�� IntroductionTCoursework.Info Coursework - http://www.coursework.info/ - Redistribution ProhibitedTCoursework.Info Coursework - http://www.coursework.info/ - Redistribution Prohibitedalexalex�� ��Oh��+'��0l���(��� � ( 4 @LT\d� IntroductionoUCoursework.Info Coursework - http://www.coursework.info/ - Redistribution ProhibitedualexewoUCoursework.Info Coursework - http://www.coursework.info/ - Redistribution Prohibitedu>Downloaded from Coursework.Info - http://www.coursework.info/is Normal.dotfalexl.d2exMicrosoft Word 10.0@@H϶]��@H϶]��@H϶]������ ��Õ.��+,��D��Õ.��+,��l(���H����� ���� � �UCoursework.Info Coursework - http://www.coursework.info/ - Redistribution ProhibitedoUCoursework.Info Coursework - http://www.coursework.info/ - Redistribution ProhibitedoUCoursework.Info Coursework - http://www.coursework.info/ - Redistribution Prohibitedo� �1d A Introduction Titled@���+K_PID_LINKBASE CopyrightDownloaded FromCan RedistributeOwner�A4http://www.coursework.comcoursework.comehttp://www.coursework.com -No, do not redistributecoursework.com/ ����!"#$%&'����)*+,-./����1234567��������:����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������Root Entry�������� �F�GP�]��<�1Table�������� WordDocument��������(>SummaryInformation(����(DocumentSummaryInformation8������������0CompObj������������j������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������ ���� �FMicrosoft Word Document MSWordDocWord.Document.8�9�q ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Communications section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Communications essays

  1. Which properties of HTTP waste bandwidth? What is the additional problem using HTTP/1.0 together ...

    replace HTML and HTTP with other languages and protocols better adapted to a wireless environment, such as Handheld Device Transport Protocol (HDTP) and the Handheld Device Markup Language (HDML). ? Push technologies: Instead of polling the content from a server, the server could alsoo push content to the client.

  2. ICT Systems in Everyday Life: Your Local Community

    The host network may be compared to an Internet Service Provider in that it is the gateway through which all the various ATM networks become available to the cardholder. The two input devices in an ATM are: 1. A card reader that captures information stored on the magnetic strip on the back of the ATM debit or credit card.

  1. Unit 23: Investigating Communications and Networks

    WWW: (World Wide Web) Also called WWW, W3, or just the Web, the World Wide Web is the whole gamut of hypertext servers that let HTML programmers present virtual, on-screen pages combining text, graphics, audio, and other file types -- not to mention links to other pages.

  2. OCR GCSE Business &amp;amp; Communication Task 7 Report

    Other annoyances involved in email can be the persistent receiving of pornography, racism or cyber bullying which can result in humiliation. We can prevent this by ensuring police are aware of this annoyance, but to further minimise the chance of email annoyance, I can install and use antivirus software, firewall and pop-up blockers.

  1. Ict ocr unit 8 ao1

    People like using phones to take pictures because it's easier than carrying a camera, on the phone they can edit photos, add frames and effects to pictures which on most cameras you cannot do. In schools kids are always taking pictures of their mates and themselves and then maybe uploading onto blogging sites.

  2. Tesco plc is the most innovative food retailer in the UK retail market.

    Tesco introduced a Clubcard loyalty program for its customers in 1995, offering points and rebates to its loyal customers. Tesco's competitors were scoffing this move not realizing that Tesco was capturing valuable information and building a strong and powerful database of its customers with every swipe of the card.

  1. Ict Access Coursework

    I believe this is because it wouldn't be able to accomplish simple tasks such as arithmetic, print outs for customer use and many more. Also another negative factor of having a paper based design is that it can easily get torn, stolen, easily be lost, can't be clearly updated, the employees hand writing may not be readable for other users.

  2. Observing Interactions between carers and clients

    Padley use with Nathan effectively was that She maintained good eye-contact, this was shown when Nathan was telling Mrs. service about a family holiday he had went to, making eye contact gave the impression to her client that she was focusing all her thoughts on what her client was saying,

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work