Greetings of the day, noble people! In continuation to The World of Data Communication, which I started last month and before taking a break from the topic. Today, I will be discussing Data Integrity, Data Security and The Server Response Codes and how they jeopardize effective Data communication. Before diving into details, here are the links to my previous posts which serve as the basis for Data communication;
Introduction To The World of Data Communication #1
DATA INTERFACES AND TRANSMISSION #2
During Data communication and networking process, the possibility of errors in data transmission can never be overlooked. Avoiding or preventing these errors is usually referred to as maintaining data integrity.
Sources of Errors
Errors in data transmission can occur for many reasons, including human errors (such as a mistake in typing a number through the application program), network errors (like those that occur during transmission through network hardware and software), electrical interference from thunderstorms or from other transmission lines. In addition, power surges or spikes due to faulty equipment can also cause bits to be lost or changed during transmission. The table below shows the summary of the most popular source of error
| Source of Error | Causes |
|---|---|
| Line outages | Storms, accidents |
| White noise | Movement of electrons |
| Impulse noise | Sudden increase in electricity (e.g., lightning) |
| Cross-talk | Multiplexer guard bands too small or wires too close together |
| Echo | Movement of electrons |
| Attenuation | Gradual decrease in signal over distance |
| Intermodulation noise | Signals from several circuits combine |
| Jitter | Analog signals change phase |
| Harmonic distortion | Amplifier changes phase |
Types of Errors
Single Bit: This is the type of error in which a 1 is changed to a 0 or a 0 is changed to a 1, single bit error can occur if we are sending data using parallel TX, for example, if 8 wires are used to send all of the eight bits of a byte at the same time and one of the wires is noise, one bit can be corrupted in each byte.
Burst Errors: This is the type of error in which two or more bit in the data unit have changed from 0 to 1 or from 1 to 0, for example, consider the case of 1000001000000011 was sent but 0100001000100011 was received. Burst error does not necessarily mean that error occurs in a consecutive bit.
Electrical Distortion Irrespective of the length of data that travels, external influences such as sound waves or electrical signals can disrupt the ease of data flow in a data communication and networking process. It may be traced to the effect of the conductors that transmit the flow of data across computers network or application software.
Random Bit Errors These errors are complications that sometimes occur during the transmission of data. These errors appear in the form of disorganized bits during the transmission of data. A typical example of this is a data sent over a transmission medium which might have thousands of bits forming a long chain of data bits. Though, there is a possibility that the bits may be reordered by accident during the process of transmission.
ERROR-CONTROL APPROACHES
Regardless of the source and cause of errors, we need some scheme to protect our data. Such methods of maintaining data integrity are often referred to as error control approaches.
I will like to discuss some approaches.
Not to check for errors. This approach may sound frivolous, but it is used by some of the dumb terminals. The device assumes that the terminal operators and not the terminal itself are able to catch any errors. In this case, a conscious decision has been made that it is more important to build a cheap terminal operator and not the terminal itself, is able to catch any errors. In this case, a conscious decision has been made that it is more important to build a cheap terminal than an error-free terminal.
A second approach is error detection with flagging. This approach requires that errors be detected or noticed when the data is received: it requires no correction of these errors, only an indication that an error exists. Some terminals display a question mark or sound a beep when they receive a character that they believe is in error. These terminals have no idea how to correct errors, but they alert the user that something has gone wrong.
A third approach is error detection with a request for retransmission. After an error is detected by the receiver, some protocols ask the sender to retransmit the message. A terminal using one of the protocols without would check all incoming messages and if a particular message contained errors, would ask the sender to transmit another copy of the message. The terminal would not display the message on the screen until it was received error free.
A fourth approach is forward error correction or FEC. In this case, the error is corrected by the receiving device. This method requires sufficient intelligence in the receiving device to determine not only where the errors are, but also how to correct it. In most cases, forward error correction is limited. For example, a scheme can be provided to correct 100% of single bit errors, when only one bit in a byte is incorrect, but the same scheme does not correct multiple bit errors in a byte.
Server Response Codes And What They Mean
Error 504 Gateway Timeout Error is a typical example of a server response code, It is just a Status code which is issued by a server in response to a request made by a client to the server. Error 504 almost confused and caused panic to many steemit users last two weeks or thereabouts, when it suddenly appeared for some minutes on the steemit website.
A question like is steemit going to crash?, is my sbd save?, how about my steem?, shouid I sell now?, e.t.c, Many people were afraid and found asking these questions across some chatting platforms.
It should be noted that: Error 504 and others are Server Response Codes and has nothing to do with the crashing of the website, other notably examples are: 100 301 405 417 450101 302 406 41 451404
*All images are from free source websites
010101010101010101010101010101010101010101010101010101010101010101
Thanks for reading through, your thoughts are important.
Until my next post,
keep on sending zeroes and ones.
If you write STEM (Science, Technology, Engineering, and Mathematics) related posts, consider joining #steemSTEM on discord here. If you are from Nigeria, you may want to include the #stemng tag in your post. You can visit this blog by @stemng for more details. You can also check this blog post by @steemstem here and this guideline here for help on how to be a member of @steemstem. Please also check this blog post from @steemstem on proper use of images devoid of copyright issues here.
