CS6501 INTERNET PROGRAMMING 2 marks with ans

CS6501 INTERNET PROGRAMMING

UNIT I

1.  Define Java.

Java is an object-oriented language similar to C++, but simplified to eliminate language features that cause common programming errors. Java source code files (files with a .java extension) are compiled into a format called bytecode (files with a .class extension), which can then be executed by a Java interpreter.

2.      How does Java achieve portability? Portability

Java programs are portable across operating systems and hardware environments. Portability is to your advantage because:

•  You need only one version of your software to serve a broad market.

•  The Internet, in effect, becomes one giant, dynamic library.

•  You are no longer limited by your particular computer platform.

3.      What is the difference between node and host?

A node is any addressable device connected to a network whereas the host is a more specific descriptor that refers to a networked general-purpose computer rather than a single purpose device (such as a printer).

4.  What is the purpose of routers?

Router operates like electronic postal workers that evaluate and forward packets between networks.

5.  Define protocol.

A protocol is a formal set of rules that must be followed in order to communicate.

6.  Why are the protocols layered?

Layering protocols simplifies the task of communicating over the network and it allows for reuse of layers that are not specific to a particular application.

7.  Define encapsulation.

Placing the data inside a package of headers is known as encapsulation.

8.  Define port.

A port is a logical channel to an application running on a host. ie., The applications running on the host machines are uniquely identified by port numbers.

9.  What do you mean by well-known ports?

Port numbers can range from 1 to 65535, however ports 1 to 1023 are reserved. These reserved ports are referred to as we1l-known ports because the Internet Assigned Numbers Authority publicly documents the applications that use them.

10. What is meant by Name Resolution?

Name Resolution is the process of mapping a hostname to its corresponding IP Address. One way to translate a hostname to an IP address is to look it up in a simple text file. The second way is the domain name service, which is a distributed database containing all registered hostnames on the Internet and their IP addresses.

11. Define protocol tunneling.

Protocol tunneling is the process of encapsulating one protocol within anotherprotocol that operates on the same layer.

12.  Define URI, URL, and URN.

1.  URI (Uniform Resource Identifier): It identifies an object on the Internet.

2.  URL (Uniform Resource Locator): It is a specification for identifying an object such as a file, newsgroup, CGI program or e-mail address by indicating the exact location on the internet.

3.   URN (Uniform Resource Name): It is a method for referencing an object without declaring the full path to the object.