Understanding Usenet, IRC, VoIP, Skype, Blogs, and RSS
Understanding Internet Communication Technologies
Usenet: The Global Bulletin Board
Usenet is a global discussion area with millions of messages organized into newsgroups. Anyone can participate in these discussions, which are hosted on many computers across the internet.
Types of Newsgroups:
- Moderated Newsgroups: A moderator reviews messages and decides which ones to post.
- Unmoderated Newsgroups: All messages are posted directly to the server and published in the newsgroup.
A newsgroup reader is software that allows you to read, respond to, and manage newsgroups.
You can also send and receive pictures and multimedia files, which need to be encoded before posting and decoded to view them.
IRC: Internet Relay Chat
Internet Relay Chat (IRC) is a way for people worldwide to chat live. IRC operates on a client/server model. To use it, you need client software on your computer and an internet connection. You log on to an IRC server with your username and choose a channel or room to start chatting.
Many IRC servers are connected to each other in a spanning tree (not directly connected).
Your message is sent from your client software to the IRC server you are connected to, and then to other IRC servers where people in the same channel are.
VoIP: Voice Over Internet Protocol
VoIP (Voice over Internet Protocol) is how phone calls are made over the internet. A special VoIP telephone must be plugged into a router or Ethernet connection. The VoIP phone converts the voice signal to digital data and compresses it, as uncompressed data can be very large.
The data is then broken into packets and sent using the TCP/IP protocol to an IP voice gateway near the receiver. The IP voice gateway combines the packets, uncompresses them, converts them back to their original form, and sends them to the normal telephone network until it reaches the receiver.
Skype: Peer-to-Peer Communication
Skype is software you can use on a PC to make free voice calls from PC to PC, though calls from PC to normal phones cost money. You can use your computer’s speakers and microphone or a special headset.
Skype uses peer-to-peer technology with no central server. When you log in, you automatically contact a “supernode.” Any computer running Skype may become a supernode without the owner’s knowledge. The supernode contacts the login server with your information, logging you into the Skype network.
When you search for users, your request is sent to a supernode. If it doesn’t have the information needed, it sends the request to another supernode, and so on.
Blogging: Sharing Your Thoughts Online
A blog is a single page used by a single blogger to write about various topics such as politics, sports, or fashion. Special software like Movable Type or sites are used to create the blog.
Most users create blogs using free websites such as Blogger. Blogs can be read by visiting the blog directly or by using an RSS reader, which allows you to read the blog without visiting the site itself.
When someone updates their blog, the website pings the RSS server to alert it that there is something new, which in turn alerts search websites about the new update.
RSS: Really Simple Syndication
RSS is typically used to get news updates or blog updates in an RSS feed.
Information to be put in the feed needs to be in XML format. XML coding includes all information sent in the feed, such as the headline, description, and a link to the full post.
The XML page is placed on a web server, and a link on the webpage leads to the XML page. An icon on the webpage lets visitors know that the page has RSS feeds.
Visitors can click on the icon and copy and paste the link into RSS software called an RSS reader or use websites that provide this service, like google.com/reader. Whenever there is an update, you will get the updates in the feed.