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

Many people assume wrong in seeing kilobits with kilobytes per second. So often, people assume that the speed they are not getting maximum results.

When you play music or video clips via the internet, players generally displays the data rate in kilobits per second (Kbps). But in the internet browser and other software transfer file (see picture below) is always displayed in units of kilobytes per second (KB / Sec or KBps), which is it different from kilobits per second (Kbps).

This causes much confusion that often occurs in layman internet customers. Customers often assume that their speed can not match those promised by the service provider.
In the world of computers one byte equals 8 bits, please refer to the list. This means that one megabyte equals 8 megabits. Then, if your browser displays the transfer rate of 194 KB / Sec (see picture above), it means the same as you to donwload on the speed of 194 x 8 kilobits per second (Kbps), or a total of 1552 Kbps.

In other words, if your customer International Dedicated 64 Kbps transfer rate will be displayed approximately 8 KB / Sec or KBps. This value is still dependent on some factors which affect speed.

READ MORE - What is the kilobits per second?

The reason why every email you send is always up to their destination because due to "tag", which contains information about the destination. Like a bag at the airport. However, "tags" (often known as "headers" in the computer world) there are values that must be charged on the bandwidth for any data sent over TCP (Transmission Control Protocol) over the Internet simultaneously. "Tag" it will burden your bandwidth by 13% (thirteen percent).


A speed measuring site on the internet does not show the actual numbers. Because many factors influence the speed test at each site. This can be caused by:

1. Differences path (routing) is different between the backbone of one another.
2. Ability of the site provider's server receives the data.
3. Owned provider of large bandwidth speed test site itself.
4. Specification of computers used when doing the speed test.
5. In other words these sites is just an illustration that can be estimated only temporary.

SPEED Enemies

Enemy 1: Badly configured PCs
The single most common cause of poor performance is a Computer That Is in poor shape for broadband. The usual problems are:

* Insufficient memory (128MB is really the lower limit now for any computer);
* Underpowered processor (vintage computers from the early 90s with a central processing unit slower than 400MHz);
* An aging and unstable operating system, accumulation of shareware, particularly spyware etc;
* Over-clocked motherboards cause unusual problems.

Enemy 2: Packet losses
The Internet is a resilient network originally built to withstand a nuclear war. One reason for this strength is TCP, the network protocol That makes sure your data gets from one point of the Net to another.

TCP is Designed around the Assumption That Some parts of an e-mail message, for example May not get through the Net.

Thus, an e-mail message to be transferred gets broken down into "packets". For example, five packets will of attempt to take the fastest route to reach the destination, and Pls do they want, the five packets will of "combine" to form the original e-mail message.

For the sake of an example, let's imagine you are downloading data from www.microsoft.com, and one of Those many packets streaming down to you disappears en-route.

Maybe a random failure or outage knocks a network router for a microsecond, and the packet is dropped. At your end, your computer notices the missing packet in the stream of sequence numbers, and so does not acknowledge its reception.

The sender notices the lack of acknowledgment, and must re-transmit the lost data. The retransmission procedure adds to the amount of data flowing over the connection, slowing down the entire transfer.

There are many TCP copes with Airways That That networks are down. But in the end, consistent packet loss along a long internet link means the Internet traffic is often slower than it Should be, even though it May be one packet in ten or twenty That is being dropped.

If the there is continuous packet loss Between you, and your favorite sites, then Web pages or files Transfers, Which follow the TCP protocol, are going to slow down to a crawl.

If you see extremely slow performance from a particular website, then you can do a ping test, Which shows how many packets are lost along the way.The instructions are as follow:

* Go to a MS-DOS prompt, and type ping-t www.download.com (or any website you want to test with)
* Watch the sequence numbers printed. Leave it running for a short time, say 30 seconds, then press control-c.
* If you see 5% or more packet loss, then TCP performance is going to be poor over this link.
* If no packets get through at all, May you have found a server That does not respond to ping packets (Some servers do this as a security measure).
* In That Case, use the command tracert (traceroute), to identity the server That is one hop from the target server, and try pinging That instead.

To do a traceroute, the instructions are as follow: -

* Open a MS-DOS window (command prompt) and use tracert, to work out at what point the congestion May be.
* For example, tracert www.download.com. Trace route shows May Nowhere in the chain Between you and your destination the problem starts, and its nature.

Enemy 3: Many servers Can not currently offer high speeds to you
Mnet though strives to offer the fastest connectivity to the rest of the world, Sometimes the weakest, or slowest, the link is the one That your website uses to connect to the Net.

Here Are Some results of a speed test connected to Trust websites reasonably well, at 12am in the morning (off peak):

In this example, Microsoft and myisp.com would not Provide the "broadband experience" to any user they want WHO thought Had speeds of 768kbps or more.

Many servers offer speeds far slower than even this, Because They are busy, and you are sharing on their bandwidth with dozens of other people.
Servers

File

Speed
1.6mb ftp.netscape.com 310k/sec
2.0mb ftp.aol.com 280k/sec
5.0mb ftp.microsoft.com 67k/sec
5.0mb ftp.myisp.com 66k/sec

All websites have pipes connecting to the Internet on their web servers. To Ensure That all users access to WHO on their sites do not get Rejected, the bandwidth of the Internet on their pipes are sliced and divided equally Among all users trying to access on their site at any one time.

So if the number of users is low, your will of some higher speeds, but if the number of users is high, much slower speeds Can be Expected.

For Indonesia's Internet users, 12am Indonesia time Is peak hour for Internet traffic in the United States. May this mean to people surfing slowdowns to U.S. websites, Because they want have to Compete for bandwidth with the rest of the American users.

Source: ipoelnet.blogspot.com

READ MORE - How fast a pace?

1. What is the speed provided by the source or sources of the Internet in this regard is the Internet Provider, or ISP.
Internet speed is usually called the bandwidth and is measured in bytes per second (bps), or bits per second (bps). The difference is 1Byte = 8bit. REMEMBER usually written B bytes while bits written b.

2. Media liaison between the user and the ISP.
media capacity should be greater than the capacity provided by the ISP source. Type of media used also affects the quality of the Internet that is accessed primarily to the level of stability.
For media cable quality and stability are the best, while for non-cable media such as wireless or anything shaped like a wi-fi or 3G and 3.5G networks is still dependent on the quality of the signal received by the modem or the Radio Frequency (RF) used .
3. Significant factor is the behavior of users in accessing the internet. When you access a website (browsing) is in fact what happens is you are doing activities such thing as download only difference with the download of a file is that you do not know how big a file that you downloaded. Not all websites have the same file, depending on the content or the content of the website. Usually a website with a lot of picture content, streaming video or online game has a fairly large file size so that was much slower compared to if we are accessing websites that contain only text files only. The greater the content of the website slower to access our website. Based on the following formula: Access time is the amount of files to be downloaded or accessed SHARED speed internet (Bandwidth).
In addition is the use of applications (software) to speed up downloading files can cause activity such as browsing becomes slow.

4. The fourth factor is the location where access to websites that we wish to save the file or the server that served him. Examples of international websites such as yahoo american server must exist in America.
It is not a problem if the ISP you use to have the same bandwidth capacity available between the local websites and to the international website but if not, surely there must be differences in access time between local websites and international websites.

5. The number of Internet users within a local area network or LAN.
Number of users also influence the speed of Internet access.
This makes sense because the more users the more files are downloaded (see factor 3) while not increasing the capacity of the internet alias fixed. And also the behavior of each user also varies.

Source: ipoelnet.blogspot.com

READ MORE - Factors that affect speed internet access

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)

A great number of IP That entered to the server, client That Could That want to enter. direct just block him "ip and mac address from the firewall configuration

1. Login to mikrotik Used Winbox

2. then from Winbox block ip

/ Ip firewall filter add chain = forward src-address = 123.123.123.10 action = drop

3. Block IP and Mac address

from Winbox

ip firewall filter add chain = forward src-address = 123.123.123.10 src-mac-address = oe: 2009: j8: kl: 9a

And do not forget to be given the sign (!) Nearby left this MAC OK

4. Chose to Tab Action Action: drop

5. click "apply" and "ok"

Source: http://mikrotik.unimedcenter.org/?p=18

READ MORE - Drop and block IP and Mac address from Mikrotik

UNDERSTANDING INTERNET Internet (inter-network) may imply extensive computer network that connects computer users a single computer with other computers and can connect with a computer from country to country around the world, in which there are many kinds of information service facilities or surfing the Internet Browsing Namely activities of "surfing" on the internet.

This activity can be in analogikan like a walk in the mall, looking at the shop-tokotanpa buy anything. Electronic mail (e-mail) facility was used to send letters / with other orajng, without knowing the limits, time, space activities and even bureaucratic Namely Searching for specific information or data on the internet Catting this facility is used to communicate directly with other people on the internet . in general, these facilities are often used to talk or chat in the internet world wide web (WWW) with the world wide web (WWW) is you can take, formatting, and display information (including text, audio, graphics and video) using Mailing list links hypertekxt facility is used to discuss electronically by using E-mail.mailing This list is used to exchange information, opinions and so forth. Newsgroups are used to berkoferensi Fasilitad distance, so you dapatmenyampaikan opinions and responses on the internet.

Download is the process of taking files from other computers via the Internet to our computer. Upload is the process of putting the files from our computer to other computers via the internet file transfer protocol (FTP) facility is used to perform retrieval elektroniok archives or files or transfer files from one computer to another computer on the Internet. Some on the internet has been available files or dokumentyang ready [to diduplikat by others for free.
This facility is used to telnet into a specific computer systems and work on other computer systems. Ghoper facility was used to locate information stored on Internet servers using a hierarchy and you can take that information

READ MORE - Understanding INTERNET