What is TCP / IP?

TCP / IP protocol type is one who allows the collection of computers to communicate and exchange data within a network (the network). Who represents the set of rules allows computers to connect to each other, usually a form / time / line / error checking for data transmission.

What makes TCP / IP to be important?

Because TCP / IP is the protocol who have applied to almost all the hardware and operating systems. There is not another piece of a series of protocols available padasemua following systems:
a. Novel Netware.
b. IBM mainframe.
c. Digital VMS system.
d. Microsoft Windows NT Server
e. UNIX workstations, Linux, FreeBSD
f. DOS personal computer.

How early presence of TCP / IP?

The concept of TCP / IP originated from the needs of DoD (Department of Defense), the U.S. will be a communication between a variety of computers who have been there. DoD computers are often connected between one organization should researchers dg organizations other researchers, and must stay in touch so that the country's defense continues to run during the disaster, like a nuclear explosion. Therefore in 1969 began the study of a series of TCP / IP. Among the objectives of this study are as follows:

1. The creation of common protocols, DoD who need a protocol be established for all networks.
2. Improving the efficiency of data communications.
3. Technology can be combined with WAN (Wide Area Network) that has been there.
4. Easily configured.

DoD 1968 ARPAnet (Advanced Reseach Project Agency) to start the study who later became the forerunner to packet switching. Packet switching is who enables communication between network layer (discussed later) where the data are executed and distributed through the network in the form of small units I would call a packet * . Each packet is carrying the address information of each who handled exclusively by the network and does not depend on other packages. Who developed this network, who use the ARPAnet as the backbone, became famous as the Internet.

Protocols TCP / IP was developed further in early 1980 and became the standard protocols for the ARPAnet in 1983. These protocols have increased in popularity in the user community when the TCP / IP are incorporated into version 2.4 of the BSD (Berkeley Standard Distribution) UNIX. This version is widely used in research and educational institution and used as the basis of some commercial application of UNIX, including Sun's SunOS and Ultrix from Digital. Because BSD UNIX to establish the relationship between the TCP / IP and the UNIX operating system, many UNIX implementations today combine TCP / IP. unit where much of the information network to communicate. Each packet contains the identity (header) sending and receiving stations, error-control information, request a service in the network layer, information on how to handle the request and any important data that must be transferred.

What services are given by the TCP / IP

Here is a service "Traditional" vicarious TCP / IP:

* Shipping files (file transfer). File Transfer Protocol (FTP) allows computer users to the other one can send or receive files to a computer network. Because the data security problem, it often requires FTP username (username) and password, although many are also accessible via FTP anonymous who, Lias not berpassword. (See RFC 959 for FTP specification)
* Remote login. Network Terminal Protocol (Telnet) allows computer users can do to log in to a computer within a network. So this means that users use the computer as an extension of the computer network. (See RFC 854 and 855 for further telnet specification)
* Computer mail. Used to implement an electronic mail system.
* Network File System (NFS). Service access remote files who allow clients to access files on remote network computers even though the files are stored locally. (See RFC 1001 and 1002 for more information)
* Remote execution. Enables computer users to run a program in a different computer. Typically useful if users who use computers is limited, whereas it requires a lot of sources who in a computer system. There are several types of remote execution, some form of basic commands, that is who can run in the same computer system and some that use "remote procedure call system", who allows the program to call the subroutine that will be run on a different computer system . (As there are examples in the Berkeley UNIX command "rsh" and "rexec")
* Name servers. Who addresses the database name used on the Internet (see RFC 822 and 823 regarding the use of illuminative purposeful name server protocol to determine the host name on the internet.)


RFC (Request For Comments) is the standard who used the internet, although there is also content for discussion or who is bollocks. Published by the IAB (Internet Activities Board) who is an independent committee of researchers and professionals who understand the technical, condition and evolution of the Internet system. A letter RFC who follow the numbers indicate the status of RFCs:

S: standard, the official standard for the internet
DS: The draft standard, the protocol final stages before it is approved as a standard
PS: Proposed Standard, a standard protocol for future consideration
I: Informational, contains discussion materials allied information
E: Experimental, experimental protocols in the stage but not on standards track.
H: Historic, protocols who have replaced or are no longer considered for standardization.

Source: ipoelnet.blogspot.com

READ MORE - Definition and History of TCP / IP

As we saw in this moment, the Internet has grown and grown to reach several million units of computers that are connected in various parts of the world. From day to day information is also contained in the Internet network is more complete, accurate, and important. . Information has become such a valuable asset that needs to get a more specific treatment. Beside that, the progress made in developing a computer operating system itself and utulitasnya had so far where the level of performance, reliability and flexibility of software is becoming the main criteria in the process of software development. With more and more important and valuable information and supported by the progress of software development, certainly attract the breaker (hackers) and intruder (intruder) to continue experimenting to find and use any existing weaknesses of the system configuration information that has been established

Departing from the above facts, there is a concept which is more often referred to as Network Security. Initially, this concept explains more about security (security) of a computer network system that connects to the Internet against threats and harassment directed toward the system. Coverage of these concepts is becoming increasingly widespread, so at this time not only talking about computer network security problems alone, but rather lead to security problems in the global information network system. Several countries in Europe and America have made even one of Network Security becomes a central point of attention of the military parties respectively.

Actually, this network security problem arises from the local computer network connectivity we have with the wide-area network (like internet). So, during our local network computer is not connected to the wide-area network, network security problem is not so important. But this does not mean giving the sense that joining the wide-area network is a matter of 'scary' and full of danger. Network Security is only describe the possibilities that will arise from our local computer network connectivity with a wide-area network.

In general, there are 3 (three) of keywords in the concept of Network Security, namely:

* The risk / hazard rate,
* Threat, and
* System fragility (vulnerability)

READ MORE - Network security: what and how

We will discuss about the market share of wireless LAN, a description of past, present and future of wireless LAN, wireless LAN and the introduction of government standards. Then we will discuss some applications for wireless LANs. According to the experience of the story and evolution of wireless LAN technology is an important part of the basic principles of wireless LAN. An understanding of where wireless LAN and its application and the organization come to help the development of technology that allows you to apply a better wireless LAN into your organization or client needs.
Wireless LAN Market Share
Wireless LAN market share seems to grow as well as fashion in most network industries, starting with the early adoption of any technology that has been available. Marketing has moved into rapid growth, where the popular standard provides a catalyst. Large difference between the overall network marketing and marketing of wireless LAN can be increased. wireless LAN, providing flexibility in implementation and no wonder they moved quickly into other market sectors.

History of Wireless LAN
The spread of wireless networks, like many technologies, such as hereditary under the auspices of the military. The military needs a convenience, easy to implement, and data exchange security method in an environment of war.
As costs decline and quality of wireless technologies increases, it becomes cost savings for companies that can incorporate the wireless into their networks. Wireless technology offers a cheap way to campus to connect buildings to each other without fiber or copper cabling.

The standardization of wireless LAN
Since wireless LAN uses radio frequencies to send, the wireless LAN is governed by the same type of law and used to regulate things like AM / FM radio. Federal Communications Commission (FCC) regulates the use of wireless LAN equipment. In the wireless LAN market today, receive some operational standards and requirements in the United States are created and maintained by the Institute of Electrical Electronic Engineers (IEEE).
Some wireless LAN Standard:

IEEE 802.11 - the original wireless LAN standard set of data transfer rate of the slowest in the transmission of light-based technologies and RF.
IEEE 802.11b - describe about some of the faster data transfer and more limited in scope transmission technology.
IEEE 802.11a - image of sending data faster than (but less in accordance with), IEEE 802.11b, and use the 5 GHz UNII frequency bands.
IEEE 802.11g - the most recent terms, based on the 802.11 standard that describes the same with the faster data transfer such as IEEE 802.11a, 802.11b and in accordance with which allows for cheaper.
IEEE 802.11n-2009 is an Amendment to the IEEE 802.11-2007 wireless networking standard to improve network throughput over the previous two standards - 802.11a and 802.11g - with a significant Increase in the maximum raw data rate from 54 Mbit / s to 600 Mbit / s with the use of four spatial streams at a channel width of 40 MHz.

Since 2007, the Wi-Fi Alliance has been certifying interoperability of "draft-N" products based on what was of the IEEE 802.11n draft 2.0 specification. [3] The Alliance has upgraded its suite of compatibility tests for Some enhancements finalized after the draft 2.0 . Furthermore, it has affirmed That's all certified draft-n products remain compatible with the products conforming to the final standards.

Source: ipoelnet.blogspot.com

READ MORE - Introduction to Wireless LANs

In the Internet world, especially when we are talking within the scope of internet cafe, bandwidth is a word that is very sensitive. Why? Because the cafe life course of selling bandwidth, even though it was not a major factor but can not be denied service quality cafe customer visits first time is how fast internet access at the cafe, the access speed is of course back again to the definition of bandwidth.
Perhaps there are among us who feel confused about the difference between bandwidth and throughput?

Here we will slightly edit a blog that discusses about the bandwidth and throughput in a more deep, with a simple language translation hopefully the readers can understand the definition of two magic sentences above.

From: http://borix69.wordpress.com/2007/12/22/mengenal-bandwith-dan-throughput/


While in office have been wearing Joko Lelono leased line for internet connection, Joko not figure out why sometimes at certain times to access a free web mail sites like mail.yahoo.com just lose speed than if Joko Lelono wearing ordinary dial-up his house at night. Whereas leased-line that he uses a 64 kbps bandwidth for both upstream to downstream want any. Why is that?
Joko Lelono naturally confused with Internet connection speeds that are inconsistent with dilanggannya bandwidth. Whereas in accordance with leased-line advertising offers that she see, theoretical speed will be faster and more stable than regular dial-up connection. But why a certain moment sometimes slower connection speeds than dialup?

That's because in addition to the concept of bandwidth, there are other concepts that affect the speed of data flow in the network, namely throughput.

Bandwidth
As we know, bandwidth is the most widely used as a measure of the speed of data flow. But whether it is bandwidth, anyway? Bandwidth is a measure of the amount of information that can flow from one place to another within a certain time. Bandwidth can be a good fit for measuring the flow of analog data to any digital data streams. Now the public has become more bandwidth if the word fit to measure the flow of digital data.

Unit used for bandwidth is bits per second or often abbreviated as bps. As we all know that bit or binary digit is a base number that consists of digits 0 and 1. This unit describes how many bits (digits 0 and 1) that can flow from one place to another in every second through a medium.

Bandwidth is a measurement concept that is very important in the network, but this concept has the disadvantage or restriction, no matter how you submit any information to any media used in penghantaran information. This is because of the laws of physics like any technological limitations. This will cause the limit to the length of the media is used, the maximum speed that can be used, like any special treatment to the media to be used.

Here are examples of medium and long table limits the maximum speed of data flow.


While the restriction to the treatment or the way data transmission such as is
delivery in parallel (synchronous), serial (asynchronous), the treatment of specific media such as media which must not be bent (fiber optics), the sender and receiver must deal directly (line of sight), compression of data sent, etc..

Throughput
Apparently the concept of bandwidth is not sufficient to explain the speed of the network and what happens in the network. For this reason the concept appears throughput. Throughput is measured actual bandwidth at any given time in the size of one day using a specific Internet route while it is downloading a file.
How do I measure the bandwidth? And how this relates to throughput? As reviewed above, the bandwidth is the number of bits that can be delivered in one second. Here is the formula of the bandwidth:
bandwidth = Sbits / s

Meanwhile, even though their throughput has units and the same formula with the bandwidth, but the throughput is more on describing the actual bandwidth (actual) at a particular time and under conditions and certain internet network that is used to download a file with a certain size. Here is the formula for comparison with the bandwidth throughput:

download time _ _ _ best = size of file / bandwidth

download time _ _ _ typical = size of file / throughput

With only the use of bandwidth as the benchmark, Joko Lelono regard should be didownloadnya file size 64 kb can be downloaded in time sekedip eye or one second, but after the measure apparently takes four seconds. So if the downloaded file size is 64 kb, whereas the download time is 4 seconds, then the actual bandwidth or can be referred to as the throughput is 64 kb / 4 sec = 16 kbps.

Unfortunately, throughput due to many reasons, sometimes very far from the maximum possible bandwidth of a medium. Some of the factors that determine the bandwidth and throughput are:
• Network appliances
• Type of data transferred
• Network Topology
• Number of network users
• Specification of the client computer / user
• Specification of the server computer
• Induction of electricity and weather
• And other reasons.

Finally, after understanding the concept of the concept of throughput in addition to bandwidth and why it could happen, Joko Lelono can begin to understand what really happened on its network. By understanding these concepts we can begin to take into account the needs of our internet connection speed and connection options are really necessary. Not just because the ads that cast a timeless promise of high bandwidth at low prices.


Have you now understand about the concept of bandwidth and throughput after reading this article, please leave a comment and you enter on this paper. Thanks 4 your attention .. :) Have you now understand about the concept of bandwidth and throughput after reading this article, please leave a comment and you enter on this paper. Thanks 4 your attention .. :)


Source: IlmuKomputer.Com

READ MORE - What is Bandwidth and Throughput?

Most efforts to improve the security system more focused on servers, although many incidents caused by user errors caused by lack of desktop systems that ensure the safety of the users activity. Incidents "klikbca.com" viruses, trojans, and tapping the credit card number by keystroke-broadcast program indicates that the user side is the weakest link in the chain of security of a system. So also the existence of computer viruses that often cause system can not work properly, or even a computer virus able to work as a tapper tapper digital signature or other crucial data. Computer viruses or other malware attack many desktop users. So safe as safe-server system, it becomes meaningless when the desktop is used does not have good security and integrity. Secure Desktop is a work environment where users can work and perform activities with the support of adequate security. Secure desktop is expected to be able to handle and support the security of user activity that requires high security like doing data entry via the Internet. This is needed eg in banking applications for the desktop, or for the General Election (Election). Unfortunately often sistme operation and desktop systems are not so considered in designing a secure system is. To meet the concept of secure desktop then a few things to consider:

* The device peripherals are controlled (no CDROM, no floppy, serial and USB), making it difficult for users to freely enter the program without a definite control.
* Protected address space so that applications that do not have high access rights can not violate these limits.
* API which is safe.
* The structure of the file (filesystem) that is safe, for example equipped with encrypted file system.

By using well-coordinated system, the user can be set so that:

* Users can only use applications that are allowed. In other words, users or viruses that exploit a user's access rights can not install new applications.
* Users can only use the file space that is allowed.
* Users can not install or modify an existing program.
* Action can not destroy the integrity of user systems, eg the presence of the virus will not interfere with any other system or user.

The language used by programs to interact with the user also is very important because the security measures that should be understood clearly and vividly by the user, such as the SSL dialog box that is raised by a web browser, often ignored by users due to language barriers. On top of things enough to make the basis that the need to develop a desktop system that supports the user should the activities of security. Desktop security considerations of safe not only from the technical side but also from the side of users and organizations.

In general, the core of network security procedures in a company's responsibilities required of a person or team, who really pay attention to the overall course of networking. These teams have to really understand, about the security procedures

READ MORE - Manajemen Network And Administrasi Sistem (Network Security)