Network Services

WWW - the worldwide web

The World Wide Web (WWW) protocol for information distribution was invented in 1989 by Tim Berners-Lee to share formatted pages of hypertext information across the Internet. Using the HTTP (Hypertext Transfer Protocol) and HTML (Hypertext Markup Language), documents appear on the Internet in a format that any computer could understand and display. The World Wide Web appeared in 1991.

HTTP remains the standard for web pages, and most web browsers display the same web page in much the same way, regardless of the type of computer being used. The first web browser, Mosaic, appeared in 1993 and led to today's main web browsers: Mozilla, Internet Explorer and Opera.

Did you know.

The World Wide Web was named by Tim Berners-Lee, who invented HTTP and said: "Alternative names I considered were Mine Of Information ("Moi", c'est un peu egoiste) and The Information Mine ("Tim", even more egocentric!), and Information Mesh.

Email

E-mail was invented by Ray Tomlinson in 1972.

A network enables email - electronic mail. Email can be sent and received at any time or place, unlike telephone calls and public-address announcements which have to be handled immediately and can often interrupt more important business.

Email gives the sender and recipient the luxury of thinking about what they are saying, and editing their words before they are sent. Since email is stored, no notes need be taken during phone calls, and old correspondence can be searched and printed. Team workers can easily share documents by attaching them to emails and sending them instantly anywhere in the world.

For most people, email is transferred using the Post Office Protocol (usually POP3).

The POP server is the incoming mail server. SMTP (Simple Mail Transfer Protocol) is the outgoing mail server. Just remember that you can "POP in" and visit someone: POP is incoming.

The main alternative to POP mail is IMAP where the mail stays centrally on the server and you read it remotely. Think of gMail. The benefit of this is that you have just one copy of your mail and you can access it from any computer. With POP, you have to download the mail to each computer and manage several separate mail archives.

The drawback of email is spam: unsolicited email. Spam is a growing problem as the mass of unwanted mail clogs up mail servers and users' email boxes, and wastes workers' time. Some users respond by using strict, automatic filtering of incoming email. The danger is that valid emails can be treated as spam and deleted.

An email address has the form of - username@domain (e.g. fred@isp.com)

Tip: to insert a clickable email link into a webpage, the HTML you need is:

mailto:fred@isp.com

You can get fancier and fill in some of the email's fields. To specify the subject of the email, do this:

mailto:fred@isp.com?subject=This is the subject of the email

You can fill in other fields too...

mailto:fred@isp.com?subject=This is the subject of the email&body=This is the body

FTP (File Transfer Protocol)

First developed in 1973, FTP is used to send files across the Internet. One of the most common uses of FTP is to upload (send) pages to your website. Common FTP programs are Filezilla, CuteFTP, WS-FTP. Many web page editors and even file managers have FTP abilities built in.

An FTP program looks a lot like a standard file manager, but it has two "panes": one is your local hard disk and the other pane shows the contents of the remote computer. File transfer is as easy as dragging files from one pane to the other.

CuteFTP in action

Usenet

Usenet is made up of newsgroups where millions of people discuss issues of joint interest. There are tens of thousands of newsgroups, and if you have an interest, there is guaranteed to be at least one newsgroup you could subscribe to.

Which newsgroups you have access to depends on which groups your ISP wants to 'feed': few ISPs would carry every newsgroup in the world (fetching all the messages involves a massive amount of downloading). Sending a 'post' to a newsgroup is nearly identical to sending an email (in fact in Netscape, newsgroups are a part of email). The only difference is that instead of the message going to a single person, it goes to the newsgroup for the world to see.

Hint: Always think carefully before sending a message to a newsgroup. Once sent, the message will be visible across the world, and once sent, it's nearly impossible to cancel it!

If you want to investigate newsgroups without setting anything up on your computer, you can use Google Groups.
Beware: Usenet is largely an unmoderated adult forum - there are many unpleasant topics and fruity language to be found there!

A Usenet post dissected and explained

How to create a new newsgroup in the ALT.* hierarchy

DHCP (Dynamic Host Configuration Protocol)

DHCP is a service provided by Internet-enabled file servers to allocate valuable Internet Protocol (IP) addresses to computers in their network on request. Most large LANs have more workstations than they do IP addresses, but not all workstations need the Internet at the same time. Organisations can save money by allocating IP addresses only when required.

Telnet

The telnet protocol, developed in 1972, lets authorised users log on to and operate a remote computer as if they were at its keyboard.

File sharing

Networks and the Internet let you easily distribute your program code, report or picture to people in your department, or anyone in the world. Small-time programmers, struggling musicians and keen artists can share their work with anyone on Earth. More than one unknown programmer or artist has become "big" by sharing files through services like Bittorrent or Tucows.

On an intranet, you can distribute files needed by all employees, such as policies, document templates and company news.

Virtual private networks

Operating a WAN, until recently, has meant the leasing expensive ISDN lines. As the Internet grew, businesses realised they could use it as a channel between their LANs to create a cheap WAN.

A Virtual Private Network (VPN) is a private network that uses the Internet to connect remote sites or users. VPN uses "virtual" connections routed through the Internet from the company's private network to the remote site or employee. It is a cheap and effective way of using existing technology to get you from "A" to "B" without anyone else seeing what is being transmitted.

Online chat

While online chat (such as ICQ and AOL Instant Messenger) may be a valuable way for teenagers to discuss Britney Spear's latest song, it can also be a valuable alternative to the telephone for organisations.

While online chat is still synchronous (happening in real time) like the telephone, it offers the advantages of being able to transmit files and save the discussion for later reference. It is also cheaper than international telephone calls, and eliminates noisy lines and foreign accents that may be hard to understand.

Remote control

Technicians and helpdesk staff can help workers with computer problems quickly and easily by using remote control software to demonstrate how an operation is performed, or fix problems by simply taking over the remote workstation as if they were at the keyboard.

The technician or helpdesk operator can remotely see the person's screen, control their keyboard and mouse and talk to them by online chat. This allows them to efficiently help colleagues anywhere in the building or anywhere in the world.

With such services, large organisations could have a single expert helpdesk in one location and offer hands-on assistance to employees across the LAN or WAN. You'd neither know or care whether your computer problem was being solved by a person in Manchester or Melbourne.

Videoconferencing

In the bad old days, meetings often required long, expensive and tiring travel. With networking, cheap cameras and microphones, distant branches of an organisation can communicate face-to-face with videoconferencing. It is immediate, cheap and convenient. It allows immediate communication between neighbouring offices or distant countries. There have been several cases of law courts using videoconferencing to hear from witnesses who could never have attended personally because of time, distance, cost or health constraints.

Collaborative work

Networked documents let colleagues work on the same project at the same time. Most documents can only be opened by one user at a time: once a user opens a document, the network puts a file lock on the document so no other user can open it. Databases, however, can usually be used by many people at once.

Professional software such as the web page editor Dreamweaver lets several people work simultaneously on the same website (but not the same page) to improve workplace efficiency.

The sharing of documents and the simultaneous collaboration often needed by teams has been made vastly easier by the development of cloud computing, particularly Google Docs.

Search Engines

The internet's so big you could never find things without a lot of help. this is where search engines come in handy.

See details on search engines here

DNS

Without the Domain Name System, you'd be entering stuff like 125.34.67.122 into your browswer to visit your favourite sites.