E-mail

E-mail

           Assalamualaikum and hi, today i want to share about e-mail, what email exactly is? previous years before we have internet connection, we used mail to sent message  from place to place. But different with email, it used a system for sending messages from one individual to another via telecommunications links between computers or terminals using dedicated software. When i was in school i dont see the important to have an email, this is because i dont have any commitment to have the email, i just see email as a trend that i must have. But when i enter the university, i see that email is very important thing that i must have, this is when we have to communicate with others and we have to share document. when we have email, it is more easier to us to send documents or others thing with others within a minute. So i want to share to you about the structure of email and how its work and others.

There are advantages and disadvantages of the email :

Email address

• What you need is
– The E-mail address of the recipient.
– user@host
– Megataman@utm.my
– Zahirima@tm.net.my
• “utm.my" is the domain name of the mail server which handles the recipient's mail.
• “Megataman" is the user name of the recipient.
• User name and hostname are separated by "@".

Email server and client

• Email client – software / program thatcan transfer e-mail from a local host to a local e-mail server.
• Email server – software/program that can send/receive e-mail from/to other email servers.
• Mailbox – An electronic mailbox is a disk file which holds email messages.

Email software (client)

• Graphical Client (User friendly)
• Examples
– Microsoft outlook

– Thunderbird

– Netscape Mail
– etc



Text mode (UNIX - mailserv, logic server)



Email Software (Server)

Install the mail server on Linux/Unix or Windows platform.

Cc & Bcc

• Carbon Copy Section (cc)
– Send a message to more than one person, all the recipients will see the list of email addresses.

• Blind Carbon Copy Section(bcc)
– The addresses won’t be seen by the recipients.
– When email is sent to a large group of people who don’t know each other.

Attachment – MIME (Multi-purpose Internet Mail Extension)

• A protocol for transmitting non-text information across the
Internet. Basically, non-ASCII data is converted to ASCII for
transmission and then converted back at the receiver.
• A specification for automatically sending objects other than
text in email messages.
• MIME is usually associated with multimedia, such as images,
audio recordings, and movies.
• Additional hardware and helper software are usually
required.
• Common MIME-compliant mailers:
– pine, metamail, Netscape messenger, MS Outlook

ASCII Code

How does email works?

SMTP (Simple Mail Transfer Protocol)

• a protocol for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an email client using either POP or IMAP. In addition, SMTP is generally used to send messages from a mail client to a mail server.

• E-mails are transferred across the Internet via Simple Mail Transfer Protocol (SMTP).
• The mail server uses SMTP to determine how to route the message through the Internet and then         sends the message. 
• When the message arrives at the recipient's mail server, the message is transferred to a POP3 server.    POP stands for Post Office Protocol. 
•  The POP server holds the message until the recipient retrieves it with his/her email software. 

POP (Post Office Protocol) 

• POP was designed to support "offline" mail processing. In the offline paradigm, mail is delivered to    a (usually shared) server, and a personal computer user periodically invokes a mail "client" program    that connects to the server and downloads all of the pending mail to the user's own machine. 

• Thereafter, all mail processing is local to the client machine. 

• Once delivered to the PC or Mac, the messages are then deleted from the mail server.

 Advantages

 – Don’t have to know the name of your machine

 – POP mail server is installed on a computer always ON

 – Use Windows interface to read email

Disadvantages 

– The email at the mail server is popped to your local machine

IMAP

 • Another popular method by which users obtain their emails is called a central mail spool.

 • What is IMAP? 

 • IMAP stands for Internet Message Access Protocol. 

 • It is a method of accessing electronic mail or bulletin board messages that are kept on a (possibly      shared) mail server. In other words, it permits a "client" email program to access remote message  stores as if they were local.

 • For example, email stored on an IMAP server can be manipulated from a desktop computer at    home, a workstation at the office, and a notebook computer while traveling, without the need to    transfer messages or files back and forth between these computers. 

Key goals for IMAP include:

– Be fully compatible with Internet messaging standards, e.g. MIME.
– Allow message access and management from more than one computer.
– Allow access without reliance on less efficient file access protocols.
– Provide support for "online", "offline", and "disconnected" access modes *
– Support for concurrent access to shared mailboxes
– Client software needs no knowledge about the server's file store format.





SMTP vs IMAP vs POP3

Bounced back email

• Bad user account name
• Bad domain name
• Domain name server is down for several days
• Some other malfunction (email too big)



Junk Mails 

• How can they get into your mailbox?
– From name card, letter heads, published papers.
– Use search engine in the newsgroup, bulletin boards, phone books.
– Dump a full user list in a server.

• How to stop the intrusion of Junk Mails?
 – Mail server providers joint effort
 – Filtering
 – Preview before downloading


SPAM

• SPAM is flooding the Internet with many copies of the same message
– Force to send message to people
– Junk electronic mail.

• Why cause problem?
– Cost-shifting – very cheap to send thousands of emails
– Fraud – not an advertisement subject
– Waste of others’ resources – stealing bandwidth
– Displacement of Normal Email – destroy the usefulness and effectiveness of email
– Ethics problem

WEB SEARCHNG

Assalamulaikum, for this week after 1 week holiday for mid semester break, i learn about web searching. In this new generation, i could not say that people nowdays dont use web searching when they use internet. We always use, but we dont realize how they works and how the process and more. After i learn this topic i know many thing about the web searching. It is more easier to me when i know how to put the keywords at the web to find exactly what i want. So i want to share to you how they works and tips to make your works more easier :)

Browser
• Can be defined as a software application used to locate
and display web.

• Popular browser

-IE (Internet Explorer)
-Nestcape
 -Mozilla Firefox
-Safari
-Opera
- Mosaic
-Google Chrome



Searching : Pattern Matching Queries

• It is also called Fuzzy Query.
• You can enter “ungrammatical sentences”, “incomplete
sentence fragments”, “disjoint phrases”, “nonsense
words”.
• The search engine gets a collection of keywords.
• Required keyword: Mark with “+” before the keyword.
• Prohibited keyword: Mark with “-” before the keyword.



Searching : Boolean Query

• A Boolean Query is a query that consists keywords but
with logical operators (AND, OR, NOT).
• X AND Y – will return URLs that contain both X and Y.
• X OR Y – will return URLs that contain either X or Y.
• X AND NOT Y – will return URLs that contain X and do
not contain Y.

Searching Tips

• Be natural
– Is cell phone harmful?
– Ask the search engine : “Cell phone” AND harmful

• Capitalize
– Always use lowercase
– star will search “Star, STAR, stAr, …”
– Type “Star” unless you really want to search “Star”.

• Use uncommon keywords
– The more specific results will return to you.
– Think a valid and uncommon keyword.

• Require words
– Add a “+” before the keyword.
– It will be in every match.

• Exclude words
– Use “-” before the keyword.
– In what situation should we use?

• Correct Spelling
– Beware of the differences between English and
American spellings (Color, Colour)- (color OR
colour).

• Stop words
– Ignore the most common words “the, is, …”
– “searching the web” and the search engine will ignore
“the web”.
– Add more relevant keyword.

• Use wildcards
– Use “*” in some search engines.
– “funk*”  funk, funky, funkiest

• Solve dead links
– If the search engine returns
http://www.hit.com/a/b/c.html which is a dead link.
– You can try http://www.hit.com/a/b/
– Or http://www.hit/com/a/ …

• Use different resources to find/search different kinds of information.
• Use successive query refinement to achieve effectivesearch queries.
• Think carefully for the keywords typed in the search engine.
• Use Boolean queries when you need combinations of keywords.


You can also visit this site if you want more information about web searching.
http://www.techrepublic.com/blog/10-things/10-tips-for-smarter-more-efficient-internet-searching/

But if youre the person that not really hardworking to read all that, i give you two video so that you can easily see how to do it. Click this link below to watch that video.
http://motto.time.com/4116259/google-search/

Thats all from me today , i hope this blog will help you in web searching ;)

 

Internet Infrastructure

     Assalamualaikum..in week 7, i just learned about internet infrastructure. In this topic i learn many things such as hierarchy of networks, internet service provider (ISP) , internet protocol and type of internet connection and access.


     What is the internet really means? Internet is the global communication network that allows almost all computers worldwide to connect and exchange information.

Hierarchy of networks

Hierarchy of networks is like from a single computer to LAN  and from LAN to ISP and from ISP to WWW. Every computer that is connected to the Internet is part of a network, even the one in our home. For example, we may use a modem and dial a local number to connect to an Internet Service Provider (ISP). At work, we may be part of a local area network (LAN), but  most likely still connect to the Internet using an ISP that certain company has contracted with. When we connect to our ISP, we become part of their network. The ISP may then connect to a larger network and become part of their network. The Internet is simply a network of networks.

Most large communications companies have their own dedicated backbones connecting various regions. In each region, the company has a Point of Presence (POP).  The POP is a place for local users to access the company's network, often through a local phone number or dedicated line. The amazing thing here is that there is no overall controlling network. Instead, there are several high-level networks connecting to each other through Network Access Points or NAPs.

Internet service provider

Internet service provider (ISP) is also known as internet access provider. It is the company that provides access to the internet.  Usually ISP provide software package, username, password and access phone number and modem. ISP are connected to one another through Network Access Points (NAPs). The example of ISP is TM.

Internet protocol

 Every machine on the Internet has a unique identifying number that is called an IP Address. The IP stands for Internet Protocol, which is the language that computers use to communicate over the Internet. A protocol is the pre-defined way that someone who wants to use a service talks with that service. The "someone" could be a person, but more often it is a computer program like a Web browser. A typical IP address looks like this: 216.27.61.137 . To make it easier for us humans to remember, IP addresses are normally expressed in decimal format as a dotted decimal number. But computers communicate in binary form like 11011000.00011011.00111101.10001001.

An IP address consist of 32 bits, often shown as 4 octets of numbers from 0-255.

So you can check your IP adress now http://whatismyipaddress.com/

Domain Name System ( DNS)

Internet services that translate domain name like www.google.com into numerical IP (internet protocol) address like 204.62.131.129).  The reason why we used DNS is because doman name in alphabetic and easily to remember instead of number. 

Hyper Text Transfer Protocol (HTTP)

HTTP defines how messages are formatted and transmitted and what actions Web servers and browsers should take in response to various command . For example, when we enter a URL in browser, this actually send an HTTP command to the web server directing it to fetch and transmit the requested page. 

Type of internet connection and access

1. Dial connection

          It used a conventional dial up modem connected to standard telephone jack with regular twisted-pair cabling. Usually used with home computers . Its advantages is inexpensive hardware and ease to set up but its disadvantage is slow connection.

     2. Cable

         Used a direct connection that usually found in office and its advantage is fast.

     3. Satellite internet access

        Satellite internet access used a direct connection. It slower and more expensive than cable internet access. It required transceiver satellite outside the home or building to receive and transmit data. It  availability is anywhere there is clear view and where a satelite dish can be mounted and received signal. Performance might degrade or stop during heavy rains or snowstorm. Example such as Astro.

    4. Fixed wireless

        It similar to satellite internet ,but it uses radio transmission tower instead of satellite tower. Its availability is only selected areas where service is available.

   5. Broadband

     Broadband is  high-speed Internet connection . Broadband transmits data digitally, which means a modem or similar device is required on your end to translate the data packages. Several different types of broadband services are available with their own advantages and disadvantages.

  6. Mobile wireless

      Virtually anywhere cellular phone service available.