Monthly Archives: August 2009

>HTML 5.0

>HTML 5 will be the next major revision to the Hypertext Markup Language. The current version used in web development is HTML 4.01. Work began on this revision in June of 2004 and was adopted by the W3C in May of 2007 for review. Although the W3C has adopted HTML 5 it is important to note that at this point it is only for revision and is not a recommendation of the W3C yet. HTML 5 will improve interoperability and reduce development costs by making precise rules for how to handle elements. This revision of HTML is proposed as the next standard for both HTML 4.01 and XHTML 1.0.

HTML 5 will offer a number of new elements that are unavailable through HTML 4.01. Some of these new elements will be replacements for common uses of generic tags and some will provide new functionality. An example of a replacement will be the introduction of nav and footer


>OSI vs. TCP/IP

>
OSI Model

The Open System Interconnection Reference (OSI) Model is used by IT professionals as a reference to describe networks and network applications. This model was started in 1977 with a goal of providing a complete set of production network protocols. There are seven layers involved in this model. The seven layers are: Application, Presentation, Session, Transport, Network, Data Link, and Physical. The layers can be remembered by using the phrase All People Seem To Need Data Processing. These seven layers help to address five main issues.

  • How a network device sends and maps data
  • How a network device receives data
  • How devices using different languages communicate with one another
  • How network devices are physically connected
  • How protocols work on a network to organize data

TCP/IP

The TCP/IP protocols (Transmission Control Protocol and the Internet Protocol) began in the early 1970s as a result of work done by Defense Advanced Research Projects Agency (DARPA). Then, in 1982 the US Department of Defense declared that TCP/IP would be the standard for all military computer networking. The TCP/IP suite provides abstraction of protocols and services through encapsulation. This is broken down into four layers: Application Layer, Transport Layer, Internet Layer, and the Data Link Layer. The basic requirements of TCP/IP are:

  • A common set of applications
  • Dynamic routing
  • Connectionless protocols
  • Universal connectivity
  • Packet-switching

OSI compared to TCP/IP

There are many obvious similarities between the OSI model and TCP/IP but there are also differences between the two. The main differences between the two relate to the layers above the OSI’s Transport Layer and the Network Layer. In TCP/IP the Session Layer and Presentation Layers are combined into a single Application Layer. Due to a requirement of TCP/IP for a connectionless protocol, the OSI model’s Physical and Data Link Layers had to be combined. When looking at the OSI model it can be hard to determine which protocols should be mapped to which layer. TCP/IP, on the other hand, does not have this problem since it is broken down into much less specific layers. The reason for OSI not being used as widely as TCP/IP is because of the associated cost. Due to the complexity and cost associated with the creation of the OSI model the government deemed the project to be unviable and in the time it took for the model to be developed TCP/IP had taken over.

Sources:
http://www.tech-faq.com/osi-model.shtml
http://en.wikipedia.org/wiki/OSI_model
http://www.wdsd.org/strut/OSI/osimodel.html
http://www.cellsoft.de/telecom/tcpiposi.htm
http://en.wikipedia.org/wiki/Internet_Protocol_Suite



>Welcome

>Welcome to my blog! The main topic I will be discussing in this blog is Internet Technology. In addition to discussing the individual technologies there will also be room to discuss the tools, theories, interfaces and other aspects which are intimately related with the technologies themselves.

Internet Technology is a vast and continuously growing and changing field, which can be hard to keep up with. A goal for this blog will be to provide useful information to readers regarding the topic of Internet Technology. A second goal which I hope to achieve through this blog is to expand my own knowledge on this expansive topic. Each of these goals can, hopefully, be achieved through weekly postings I will have on new topics.

As previously mentioned, Internet Technology is a very broad topic which is continuously growing and changing so I will not attempt to exhaust the list of possible discussions but I will aim to hit on main subjects and current issues related to the field of Internet Technology. Possible topics for discussion here could be HTML, Mobile Web Technologies, Web 2.0, E-Commerce, Search Engine Optimization (SEO) or development languages and frameworks, to name a few. So as you can see this blog will discuss not only new technologies but I will also discuss existing technologies which we may interface with on a day-to-day basis.

Enjoy!