* How the Internet works
* Packet-switching technology
Actual data transmission takes place sporadically, rather than continuously. Data to be transmitted is divided into small packets of information and labeled to identify the sender and recipient. These are sent over a network and then reassembled at their destination. If any packet did not arrive or was not intact, original sender requested to resend the packet. -> This enables millions to transmit data at the same time.
* Understand the importance of standards (protocols)
* What problems are and tasks are involved in networks and why are standards important for networks to run?
Computers and applications of ...view middle of the document...
DNS servers convert Internet names to IP addresses.
* How the World Wide Web works
The browser breaks the URL in to parts (protocol, server name and file name) -> The browser communicates with a DNS to translate the server name in to an IP address -> Given the IP, the browser forms a connection to the server -> Following the HTTP protocol, the browser sends a (GET) request to the server and asks for the file -> The server then sends the HTML text for the web page to the browser. The browser reads the HTML tags and formats the page onto your screen
* Client server architecture
A network in which one or more computers are servers and provide services to the other computers which are called clients
* Role of routers in networking – fault tolerance, decentralization etc.
Routers are computing devices that connect networks and exchange data between them, typically connected with more than one outbound path, so that in case one path becomes unavailable, an alternate path can be used.
Decentralization, fault tolerance, and redundancy keep the network open and reliable.
* UDP, VoIP, 3G, 4G
User Datagram Protocol (UDP) works as a TCP stand-in speed is needed and quality has to be sacrificed.
VoIP allows voice and phone systems to become and application traveling over the internet.
3G – GSM/CDMA – GSM is the most used around the world. CDMA is limited by its inability to support voice and data communication at the same time
4G – LTE/WiMax – 4G offers them option of entering mobile phone business and offer a wider range of services. If speeds of 4G networks increase, more users could switch from cable, DSL and fiber to wireless internet access
* Last-mile problem
Though the internet backbone is very fast, a system’s speed is determined by its slowest component or the last mile.
* Net Neutrality issues
Net neutrality is the principle that all internet traffic should be treated equally.
Internet firms say it is vital to maintain the openness of the internet.
Telecommunications firms say they should be able to limit access to services that overtax their networks
* How search engines work
Gather the contents of all web pages (using a program called a crawler or spider or robot) -> Organize the contents of the pages in a way that allows efficient retrieval (indexing) -> takes in a query, determine which pages match, and show the results (ranking and display of results)
* How Google’s PageRank works
‘Important pages are pointed by other important pages’
Each link from one page to another is counted as a ‘vote’ for the destination page. But the importance of the starting page also influences the importance of the destination page. And those pages scores, in turn, depend on those linking to them. Pagerank places more importance to votes that come from pages with large number of votes (and so on, and so on)
* Briefly describe what the following terms/concepts mean: keyword, crawler