Monday, May 28, 2012

Assignment Post 3

Wow, i have been missing out on many IST lessons. Some are due to science competitions, some are because I have been away, exams and also some because I need to study for exams. :D but overall I might have not been having progress with my assignment, I am definitely well and truly finishing the tasks. So next lesson of IST is 4th June. And sir is teaching us how to start off our assignment. Cant wait.

Tuesday, May 22, 2012

Assignment Post 2

Today I basically did some tasks for term 2. It was the "Some Key Terms" task. From that activity I learnt about protocols and ip addresses. Sir also talked about the topics in more detail. I wrote some notes.

Some Key Terms



Define Protocol:
Protocol is usually an agreed-upon or standardized method for transmitting data and/or establishing communications between different devices.
What are these Protocol's used for?
  • TCP/IP
  • http
  • smtp
  • pop
  • FTP

A Family of Protocols

TCP/IP is a large collection of different communication protocols based upon the two original protocols TCP and IP.

TCP - Transmission Control Protocol

TCP is used for transmission of data from an application to the network.
TCP is responsible for breaking data down into IP packets before they are sent, and for assembling the packets when they arrive.

IP - Internet Protocol

IP takes care of the communication with other computers.
IP is responsible for the sending and receiving data packets over the Internet.

HTTP - Hyper Text Transfer Protocol

HTTP takes care of the communication between a web server and a web browser.
HTTP is used for sending requests from a web client (a browser) to a web server, returning web content (web pages) from the server back to the client.

HTTPS - Secure HTTP

HTTPS takes care of secure communication between a web server and a web browser.
HTTPS typically handles credit card transactions and other sensitive data.

SSL - Secure Sockets Layer

The SSL protocol is used for encryption of data for secure data transmission.

SMTP - Simple Mail Transfer Protocol

SMTP is used for transmission of e-mails.

MIME - Multi-purpose Internet Mail Extensions

The MIME protocol lets SMTP transmit multimedia files including voice, audio, and binary data across TCP/IP networks.

IMAP - Internet Message Access Protocol

IMAP is used for storing and retrieving e-mails.

POP - Post Office Protocol

POP is used for downloading e-mails from an e-mail server to a personal computer.

FTP - File Transfer Protocol

FTP takes care of transmission of files between computers.

NTP - Network Time Protocol

NTP is used to synchronize the time (the clock) between computers.

DHCP - Dynamic Host Configuration Protocol

DHCP is used for allocation of dynamic IP addresses to computers in a network.

SNMP - Simple Network Management Protocol

SNMP is used for administration of computer networks.

LDAP - Lightweight Directory Access Protocol

LDAP is used for collecting information about users and e-mail addresses from the internet.

ICMP - Internet Control Message Protocol

ICMP takes care of error-handling in the network.

ARP - Address Resolution Protocol

ARP is used by IP to find the hardware address of a computer network card based on the IP address.

RARP - Reverse Address Resolution Protocol

RARP is used by IP to find the IP address based on the hardware address of a computer network card.

BOOTP - Boot Protocol

BOOTP is used for booting (starting) computers from the network.

PPTP - Point to Point Tunneling Protocol

PPTP is used for setting up a connection (tunnel) between private networks.
What does GUI stand for?What was used before GUI?
In computer lingo, the letters “GUI” stand for graphical user interface. Basically this means that when you point your mouse or cursor to a particular icon and click on it, a hidden list of commands is automatically created for your computer to follow. GUI has replaced the need to enter DOS commands. Before GUI, PUI (PARC User Interface) was in use.

There are two methods of data transmission – serial and parallel. Explain the difference between them.

Digital data transmission can occur in two basic modes: serial or parallel. Data within a computer system is transmitted via parallel mode on buses with the width of the parallel bus matched to the word size of the computer system. Data between computer systems is usually transmitted in bit serial mode . Consequently, it is necessary to make a parallel-to-serial conversion at a computer interface when sending data from a computer system into a network and a serial-to-parallel conversion at a computer interface when receiving information from a network. The type of transmission mode used may also depend upon distance and required data rate.

Parallel Transmission

In parallel transmission, multiple bits (usually 8 bits or a byte/character) are sent simultaneously on different channels (wires, frequency channels) within the same cable, or radio path, and synchronized to a clock. Parallel devices have a wider data bus than serial devices and can therefore transfer data in words of one or more bytes at a time. As a result, there is a speedup in parallel transmission bit rate over serial transmission bit rate. However, this speedup is a tradeoff versus cost since multiple wires cost more than a single wire, and as a parallel cable gets longer, the synchronization timing between multiple channels becomes more sensitive to distance. The timing for parallel transmission is provided by a constant clocking signal sent over a separate wire within the parallel cable; thus parallel transmission is considered synchronous .

Serial Transmission

In serial transmission, bits are sent sequentially on the same channel (wire) which reduces costs for wire but also slows the speed of transmission. Also, for serial transmission, some overhead time is needed since bits must be assembled and sent as a unit and then disassembled at the receiver.
Serial transmission can be either synchronous or asynchronous . In synchronous transmission, groups of bits are combined into frames and frames are sent continuously with or without data to be transmitted. In asynchronous transmission, groups of bits are sent as independent units with start/stop flags and no data link synchronization, to allow for arbitrary size gaps between frames. However, start/stop bits maintain physical bit level synchronization once detected.

Applications

Serial transmission is between two computers or from a computer to an external device located some distance away. Parallel transmission either takes place within a computer system (on a computer bus) or to an external device located a close distance away.
A special computer chip known as a universal asynchronous receiver transmitter (UART) acts as the interface between the parallel transmission of the computer bus and the serial transmission of the serial port. UARTs differ in performance capabilities based on the amount of on-chip memory they possess.

Examples

Examples of parallel mode transmission include connections between a computer and a printer (parallel printer port and cable). Most printers are within 6 meters or 20 feet of the transmitting computer and the slight cost for extra wires is offset by the added speed gained through parallel transmission of data.
Examples of serial mode transmission include connections between a computer and a modem using the RS-232 protocol . Although an RS-232 cable can theoretically accommodate 25 wires, all but two of these wires are for overhead control signaling and not data transmission; the two data wires perform simple serial transmission in either direction. In this case, a computer may not be close to a modem, making the cost of parallel transmission prohibitive-thus speed of transmission may be considered less important than the economical advantage of serial transmission.


Define the term “URL”.Explain the components that make up the url.
Abbreviation of Uniform Resource Locator (URL) it is the global address of documents and other resources on the World Wide Web.The first part of the URL is called a protocol identifier and it indicates what protocol to use, and the second part is called a resource name and it specifies the IP address or the domain name where the resource is located. The protocol identifier and the resource name are separated by a colon and two forward slashes.A URL for HTTP (or HTTPS) is normally made up of three or four components:
  1. A scheme. The scheme identifies the protocol to be used to access the resource on the Internet. It can be HTTP (without SSL) or HTTPS (with SSL).
  2. A host. The host name identifies the host that holds the resource. For example, www.example.com. A server provides services in the name of the host, but there is not a one-to-one mapping between hosts and servers. Host names explains more about host names.
    Host names can also be followed by a port number. Port numbers explains more about these. Well-known port numbers for a service are normally omitted from the URL. Most servers use the well-known port numbers for HTTP and HTTPS , so most HTTP URLs omit the port number.
  3. A path. The path identifies the specific resource within the host that the Web client wants to access. For example, /software/htp/cics/index.html.
  4. A query string. If a query string is used, it follows the path component, and provides a string of information that the resource can use for some purpose (for example, as parameters for a search or as data to be processed). The query string is usually a string of name and value pairs, for example, q=bluebird.
In the context of data transmission, what is “error detection”?
In communications, error detection refers to a class of techniques for detecting garbled messages. Two of the simplest and most common techniques are called checksum and CRC. More sophisticated strategies include MNP and CCITT V.42 .
Why would error detection be important for the internet?
Error Detection is important because the receiver detects an error, it can be corrected, or it can simply be reported. 
Name and explain one common method of error detection.

Parity Method for Error Detection

The movement of digital data from one location to another can result in transmission errors, the receiver not receiving the same signal as transmitted by the transmitter as a result of electrical noise in the transmission process. Sometimes a noise pulse may be large enough to alter the logic level of the signal. For example, the transmitted sequence 1001 may be incorrectly received as 1101. In order to detect such errors a parity bit is often used. A parity bit is an extra 0 or 1 bit attached to a code group at transmission. In the even parity method the value of the bit is chosen so that the total number of 1s in the code group, including the parity bit, is an even number. For example, in transmitting 1001 the parity bit used would be 0 to give 01001, and thus an even number of 1s. In transmitting 1101 the parity bit used would be 1 to give 11101, and thus an even number of 1s. With odd parity the parity bit is chosen so that the total number of 1s, including the parity bit, is odd. Thus if at the receiver the number of 1s in a code group does not give the required parity, the receiver will know that there is an error and can request that the code group be retransmitted.
 
An extension of the parity check is the checksum in which a block of code may be checked by sending a series of bits representing their binary sum. Parity and checksums can only detect single errors in blocks of code, double errors go undetected. Also, the error is not located so that correction by the receiver can be made. Multiple-error detection techniques and methods to pinpoint errors have been devised (See Section 21.3 of Bolton) and texts such as Audio, Video, and Data Telecommunications by D. Peterson (McGraw-Hill 1992) explain these in more detail.
What is HTML and explain why it is important?
HyperText Markup Language (HTML) is the main markup language for web pages. HTML elements are the basic building-blocks of webpages. It is important because it helps create webpages.



Monday, May 21, 2012

Assignment Post 1

Today we were told about the term 2 IST Assignment. It is a website development project using Sharepoint Designer 2007. Today's lesson we only wrote notes and sir explained the assignment. Basically we are given 6 topics to research on and we have to choose 2 from them. Here are the topics below:

Topics for Web assignment



1.      What is spam and how to avoid it

2.      Broadband and bandwidth explained

3.      What is the cloud and why would you want it

4.      What is Google+

5.      What are some social implications of geotagging

6.      What are google glasses/augmented reality

We have to write about 2 of our choosen topics in the website. The website should also have a login, menu and hyperlinks. I am very excited about this. I am thinking of doing "google plus" and "spam". Because Sir showed us some videos about them and they look very interesting.

Thats all for todays lesson. Getting more information next lesson (tomorrow) and hopefully starting. :D

Notes

  • an agreed method of comunicating:Protocol
  • every device on the internet has an IP address which is unique





Monday, May 14, 2012

Smart Phone Tour


Technology is about hardware and software

Hardware are things like mobile phone, computers, digital camera, USB, colour printer, Router and internet connection and a computer network, which is usually a lan network (Local Area Network). Hardware is things you can touch.Software are things like a file transfer application, various image softwares were used to resize and inserted arrows also cropped some pictures , We used online applications to generate QR codes which were called QR generator, we used a QR code reader, Google Docs (online collaboration), voice recorder, we used Google sites to host our websites.

Constraints-limitations


Time and internet speed were constraints. We had issues uploading images. The user of our system were downloading therefore this becomes a constraint. The pictures have to be small, so that the download time is reasonable. We needed to create a good user experience; we didn’t want them standing forever. The whole thing should be downloaded in 10 seconds. We had JPEG images and WMV files which we had to keep them very small by using compressed file formats. We had to limit the resolution of the images. Our images were around about 400 by 350 pixels.  There had to be no cost for the user. The QR reader had to be free. We had free available hosting services. Google sites are free web hosting and creations.

My Role


I had to make 2 websites one was a tour from Visual Arts to the BM Building and the other one was the Visual Arts Tour to the Science Lab Rooms. We also made our own QR Codes and our own sites.

Problems


If the internet was slow then we would save stuff on our usb so we could do it at home. We needed a way to get the QR reader on the viewer’s phone. There were roughly 500 photographs. Therefore we sorted them into folders. We didn’t know the status of each website therefore use a shared document which was a big grid which showed all the different websites. Teachers had edit permission to the sites, for last minute changes to be made.

History Of The Internet

How did the internet originate?
The Internet originated from a defense project called ARPANET. A group of scientists who had access to supercomputers needed to share information across large distances and what they came up with was the Internet.it all began with a satellite.It was 1957 when the then Soviet Union launched Sputnik, the first man-made satellite. Americans were shocked by the news. The Cold War was at its peak, and the United States and the Soviet Union considered each other enemies. If the Soviet Union could launch a satellite into space, it was possible it could launch a missile at North America.President Dwight D. Eisenhower created the Advanced Research Projects Agency (ARPA) in 1958 as a direct response to Sputnik's launch. ARPA's purpose was to give the United States a technological edge over other countries. One important part of ARPA's mission was computer science.In the 1950s, computers were enormous devices that filled entire rooms. They had a fraction of the power and processing ability you can find in a modern PC. Many computers could only read magnetic tape or punch cards, and there was no way to network computers together.ARPA aimed to change that. It enlisted the help of the company Bolt, Beranek and Newman (BBN) to create a computer network. The network had to connect four computers running on four different operating systems. They called the network ARPANET.Without ARPANET, the Internet wouldn't look or behave the way it does today -- it might not even exist. Although other groups were working on ways to network computers, ARPANET established the protocols used on the Internet today. Moreover, without ARPANET, it may have taken many more years before anyone tried to find ways to join regional networks together into a larger system.
Who were the people most responsible for creating it?







Notes From The Videos..
through the US Military. They were worried about attacks taking their computers. They thought it would be a good idea if the computer could talk to each other. Therefore they started a network called "arpa net" which stands for advanced research project agency.2009-50 years 1957, internet started compueteer only worked on one taks at a time. macth processing. They had to be stored in cold rooms.a remote connecteion had to be installed so that the sdelvelopers could work speratly on computers. TIME SHARING where people can work on a main computer all at once.the first un man satillete was sent into orbit. in order to secure americas technonogloy.ARPANET.
military finacnical commercial 4 netwroks arounf the world that shaterd toshare networks. Instead of duplicatly things they could be shared around the world.


TCP transmission control protocol where data is chopped into bpackets and sent off.
for sending packets and assemblying.
communicastions worked trhoguh radio waves
then they used direct waves which didnt have a long range.
Internet the term was bONMR CHECK IT OUT
to keep all the informayion systems functionings that was the need of the internet. they deleveloped prototcols to talk to each other. s agreed way of doing something.
compueter have protocols of commmunicating with other servers.
protocols are very important.TCP/IP is agreed way of sending data
EVERY COMPUTER AHAS  a address called IP address.Its like a packet of information.
It travels around the network from different bits of hardware.TCP/ip is a protocol transmission control protocol.  Is how computer works Internet proptocols
 MAIN FRAME very powerfulmcomputers