1. Define protocol.
A protocol is a set of rules that govern data
communication. In networks, communication occurs between the entities in
different systems. Two entities cannot just send bit streams to each other and
expect to be understood. For communication, the entities must agree on a
protocol.
2. Define UDP.
UDP (User Datagram Protocol) is a
connectionless unreliable transport protocol. It extends IP’s host-to-host
delivery service to process-to-process communication service.
3. Define DNS.
The
Domain Name System (DNS) is a hierarchical naming system built on
a distributed database for computers, services, or any resource connected to
the Internet or a private network. DNS is an Internet service that translates domain names into IP
addresses.
4. Define TCP/IP.
TCP (Transmission
Control Protocol) is a reliable, point-to-point, connection-oriented,
full-duplex protocol.
5. Define WWW.
The World
Wide Web (WWW) or the web is a repository of information spread all over
the world and linked together. The WWW is a distributed client-server service
in which a client using a browser can access a service using a server. The
services provided are distributed over many locations called web sites.
6. Define FTP.
File
Transfer Protocol, it is a set of rules that enables a user to log on to
another computer and transfer information between those computers. This can be
used even if the file size is larger and there are too many files.
7. Define HTTP.
It is a form of communication protocol which gives a
detailed specification of how web clients and web servers should communication.
8. Syntax of HTTP request message.
Every HTTP request message has the
same basic structure:
Start
line
Header
fields (one or more)
Blank
Line
Message
Body (optional)
9. Syntax of HTTP response message.
Every HTTP
request message has the same basic structure:
Status line
Header fields
(one or more)
Blank Line
Message Body (optional)
10. What are URI, URN and URL?
URI – Uniform
Resource Identifier is an identifier that is associated with a particular
resource. (such as web page or graphics image on the WWW).
URL – Uniform
Resource Locator, it represents the location of a resource on the web.
URN –
Uniform Resource Name, it is a unique name for a resource.
11. What is MIME?
MIME
- Multipurpose Internet Mail Extensions.
MIME consists of three basic pieces.
1.
A collection of header lines. These
header lines describe the data being carried in the message body. They include
§ MIME-Version:
the version of MIME being used,
§ Content-Description: a
human-readable description of what is in the message similar to the Subject,
§ Content-Type: the
type of data contained in the message,
§ Content-Transfer-Encoding:
how the data in the message body is encoded.
2.
Content Type definitions.
3.
The encoding technique followed by the
various data types is described.
12. What are the different MIME types?
The
different MIME types are
Text/html – HTML
document
Image/gif
– image represented using Graphics Interchange Format.
Image/jpge
- image represented using Joint Picture Expert Group Format.
Text/plain
– human readable text with more embedded formatting information.
Application/octet_stream
– arbitary binary data
Application/x-www-form-urlencoded
– data send from a web form to web server for processing.
13. Define web clients.
Web
client is a software that accesses a web server by sending an HTTP request
message and processing the resulting HTTP response. Web browsers running on
desktop or laptop computers are the most common form of web client software.
14. Define user agent.
Any
web client that is designed to directly support user access to web servers is
known as user agent.
15. Define web server.
Web server accepts HTTP request from web clients and
return an appropriate resource in the HTTP response.
16. Functions of web client.
The
functions of web clients are
1. Reformat
the URL entered as a valid HTTP request message.
2. If
the server is specified using a host name, use DNS to convert this name to
appropriate IP address.
3. Establish
a TCP connection using the IP address of the specified web server.
4. Send
the HTTP request over the TCP connection and wait for the server’s response.
5. Display
the document contained in the response.
17. List out the server features.
The
features of web server are
1. The
server calls on TCP software and waits for connection requests to one or more
ports.
2. When
a connection request is received, the server dedicates a sub task to handle
this connection.
3. The
sub task establishes the TCP connection and receives a HTTP request .
4. The
sub task examines the host header field of the request to determine which
virtual host should receive this request and invokes software for this host.
5. The
virtual host software maps the request URI field of the HTTP request line to a
resource on the server.
6. If
the resource is a file, the host software determines the MIME type of the file
and creates an HTTP response that contains the file in the body of the response
message.
7. If
the resource is a program the host software runs the program, providing it with
the information from the request and returning the output from the program as
the body of the HTTP response message.
8. The
server normally logs information about the request and response in a plain text
file.
9. If
the TCP connection is kept alive, the server sub task continues to monitor the
connection until a certain length of time has elapsed.
18. What is tuning?
Changing
the values of server parameters in order to optimize performance is known as
tuning the server.
19. Define log.
A
file that records the information about every HTTP request processed by the
server is referred to as log.
20. What is the need for access
control?
Access
control is a system which enables an authority to control access to areas
and resources in a given physical facility or computer-based information
system. It is needed for providing secure access to the available resource.
21. Define eaves dropper.
Any
machine other than the sender or receiver that extracts information from
network message is known as an eaves dropper.
22. What is meant by man in the middle
attack?
Any
machine that intercepts a message intended for another machine, prevents the
message from further forwarding, and returns an HTTP reply to the sender
pretending to be from the target.
23. What is container and stand alone
tag?
Container
tag is a tag that contains both start and end tag.
e.g.:
<B> text to be bold </B>
Stand
alone tag is a tag that has a start tag but does not have a end tag.
24. List some stand alone tags.
<br>
<hr>
<image>
25. Define DTD.
The
abstract syntax for each flavor of XHTML 1.0 is defined by a set of text files
known collectively as an XML DTD (Document Type Definition)
26. Define Relative and absolute URL.
The
relative URL points to a file or
directory in relation to the present file or directory. It is easy to move a
file from one directory (folder) to another, or a web site from one domain name
to another.
An
absolute URL is the URL most people
already understand. It is the complete path including the domain - file name.
Example: http://www.ibdhost.com/images/logo.gif specifies an image file
(logo.gif) located in the images directory, for the www.ibdhost.com domain
27. What is HTML and XHTML?
Hyper
Text Markup Language is the primary scripting language for developing web
pages. HTML documents are written using HTML tags embedded in angular brackets.
XHTML (eXtensible HyperText Markup Language) is a family of XML markup languages that mirror or
extend versions of the widely used Hypertext Markup Language (HTML), the
language in which web pages are written.
28. Define Internet.
The
Internet is a global system for interconnection of computer networks
that use the standard Internet Protocol Suite (TCP/IP) to serve billions of
users worldwide. It is a network of networks that consists of millions
of private, public, academic, business, and government networks, of local to
global scope, that are linked by a broad array of electronic, wireless and
optical networking technologies.
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