Thursday, December 25, 2008

Internet Engineering Task Force

The Internet Engineering Task Force (IETF) develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standard bodies and dealing in particular with standards of the TCP/IP and Internet protocol suite. It is an open standards organization, with no formal membership or membership requirements. All participants and leaders are volunteers, though their work is usually funded by their employers or sponsors; for instance, the current chairperson is funded by VeriSign and the U.S. government's.

BBN initially chose a rugged zed version of Honeywell's DDP-516 computer to build the first-generation IMP. The 516 was originally configured with 24 kB of core memory (expandable) and a 16 channel Direct Multiplex Control (DMC) direct memory access control unit. Custom interfaces were used to connect, via the DMC, to each of the hosts and modems. In addition to the lamps on the front panel of the 516 there was also a special set of 24 indicator lights to show the status of the IMP communication channels. Each IMP could support up to four local hosts and could communicate with up to six remote IMPs over leased lines.

Thursday, December 18, 2008

Hypertext Transfer Protocol

Hypertext Transfer Protocol (HTTP) is a communications protocol. Its use for retrieving inter-linked text documents (hypertext) led to the establishment of the World Wide Web.

HTTP development was coordinated by the World Wide Web Consortium and the Internet Engineering Task Force (IETF), culminating in the publication of a series of Requests for Comments (RFCs), most notably RFC 2616 (June 1999), which defines HTTP/1.1, the version of HTTP in common use.

HTTP is a request/response standard between a client and a server. A client is the end-user, the server is the web site. The client making a HTTP request—using a web browser, spider, or other end-user tool—is referred to as the user agent. The responding server—which stores or creates resources such as HTML files and images—is called the origin server. In between the user agent and origin server may be several intermediaries, such as proxies, gateways, and tunnels. HTTP is not constrained to using TCP/IP and its supporting layers, although this is its most popular application on the Internet. Indeed HTTP can be "implemented on top of any other protocol on the Internet, or on other networks. HTTP only presumes a reliable transport; any protocol that provides such guarantees can be used."

Thursday, December 11, 2008

Publishing Web pages

Web page production is available to individuals outside the mass media. In order to publish a Web page, one does not have to go through a publisher or other media institution, and potential readers could be found in all corners of the globe.

Many different kinds of information are available on the Web, and for those who wish to know other societies, cultures, and peoples, it has become easier.

The increased opportunity to publish materials is observable in the countless personal and social networking pages, as well as sites by families, small shops, etc., facilitated by the emergence of free Web hosting services.

Thursday, December 4, 2008

Head and Brain Malformations

Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's a genetic problem. In other cases, exposure to certain medicines, infections or radiation during pregnancy interferes with brain development. Types of brain malformations include missing parts of the brain, abnormal growth of certain parts of the brain, and incomplete division of the brain.

There are head malformations that do not involve the brain. Craniofacial disorders are the result of abnormal growth of soft tissue and bones in the face and head. It's common for new babies to have slightly lopsided heads, but parents should watch the shape of their baby's head for possible problems.