KDE 4.4 dev: What’s new?
I have managed to find some time to cover the recent changes in the development version of KDE 4.4. The number of changes is not impressive but they are interesting enough to write an article.
[Read the rest of this entry...]
Media PC on Linux
As an experiment I decided to build Media PC based on Linux. First of all I was wondering, how much did the Linux distributions evolve in the past few years (I’ve used Linux since a few years only on servers). The second thing is, I was fascinated by quite new, miniaturized hardware solutions based on Intel Atom processors. The third was, I wanted to check in real life the suitability of so called Media P..
Concerning the last one, after a tentative googling I made a few assumptions, which I’d like to achieve:
- watching films/pictures in HD on my TV set;
- listening to music (including webcast);
- browsing on the TV set;
- using everything as a simple NAS (Network Attached Storage) – mainly for a backup.
And the usage of all hardware should be not much involving, which means that I’d like it to ensure:
- an easy allocation of media (that is data) in the device;
- easy handling – the best option would be a remote control;
- a quick start – optimal using a hibernation mechanism.
It’d also be good if the hardware was silent and didn’t use much energy. Not meaningless would be also fitting it all into a small and aesthetic case – looking more like an audio player than a PC (only with this assumption you can negotiate with the fair sex leaving the machine in a saloon – that is close to the TV set).
TCP/IP and OSI
TCP/IP and OSI are the two networking models that builds nowadays networks. A networking model is an organized of set of documents that describes functions required in a network.
We live completely relax about computers and mobile devices having communications among themselves. However, once upon a time, when there were no networking and every vendor made their devices to communicate only with others of their brand, this communication was hard to occur. So, it was necessary to create an open standardized networking model that all vendors would support. It gave origin to the design and development of the Open System Interconnection (O.S.I. model). A few years later, the U.S. Defense Department opened a contract to develop a new network model. Then, it was the origin of what was called the TCP/IP networking model.
TCP/IP architectural model and example protocols.
[table "<the_table_ID>" not found /]
| TCP/IP Architecture Layer | Example Protocols |
|---|---|
| Application | HTTP, POP3, SMTP |
| Transport | TCP, UDP |
| Internet | IP |
| Network Access | Ethernet, Frame Relay |
The TCP/IP Application Layer.
This netwokr layer provides an interface between software running on a computer and the network itself.
The TCP/IP Transport Layer.
The TCP/IP transport layer consists of 2 main protocols: the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP).
This post will be continued with more information about the TCP/IP layers, protocols involved as well as the OSI network model.
Introduction to Computer Networking Concepts
Whenever you browse on Internet using your PC or mobile device you use a hidden whole of devices (not necessarily of your own) and protocols that allow the inter-connection to be established.
Many years ago, the most common device used to connect to a network (Internet, for example) was a dial-up modem. Nowadays, dial-up connections are decreasing significantly and are being replaced mostly by ADSL. I am not interested in to describe the whole network evolution. I prefer to speak about the protocols and devices focused in the CCNA certification.
In this chapter, I’ll be focused on the most important concepts about Computer Networking.
“History of the Internet” video.
Every networked enterprise is that which allows employees to communicate with each other using what we call an enterprise network. However, a network is not available just for medium size or big companies. Since a long time, common people at their houses enjoyed a small office/home office, or SOHO. When we sum SOHO’s plus company networks and mix them into public communication we get the widely known Internet (short form of interconnected networks).
Two or more wired or wireless interconnected devices make a network. To describe and manage the underlaying technology used to communicate these devices is the main focus of the CCNA. A networking model or networking architecture is an organized set of documents which individually describes one small function required to make a network.
There are 2 widely used networking models used by CISCO devices: The TCP/IP (Transmission Control Protocol) and the OSI (Open System Interconnection) reference model.
In the next chapter of this CISCO CCNA Crash Course you’ll be introduced to the TCP/IP model. You’ll study protocols involved on it. The same is going to be done for the OSI model.
Bookmark this site and check it out often. Your support is highly appreciated, please consider my consultancy services and purchase a product announced in this site (your CISCO CCNA official study book, for example).