Characteristics of Networks Types - Assignment Example

The paper discusses the kind of network of personal area network that could also be interconnected lacking wires to the Internet or other even networks.

To a larger extent, this is true. Unlike other types of networks that are specifically fixed to an office location network-wise, metropolitan area network span to the furthest boundary of a city. A metropolitan area network (MAN) can be referred to as a network that interconnects users in a geographic area or region larger than a large local area network (WAN) can cover but at the same time smaller than a wide area network (WAN can cover. The statement is further true as the term MAN` is applied to the interconnection of the networks in a city into a single larger network.

List the OSI layer that performs each of the following functions:


1. data compression


presentation layer,

1. multiplexing

session layer

1. routing


 Networking layer

1. definition of a signal’s electrical characteristics

 Physical layer

1. e-mail

Application layer


f. error detection  

 Data link layer

1. end-to-end flow control

 Transport layer.

For each function in the previous exercise, list the

TCP/IP protocol suite layer that performs that

function.


You are sending and receiving text (instant) mes-

sages (IMs) with a friend. Is this IM session a logical connection or a physical connection? Explain your answer

when sending an instant text it is a logical connection as immediate feedback is expected.

an important concept is the understanding of the link between the sender and the receiver of communication.

Chapter 5 Data security

1          Explain the differences between a database user and an application user.

            A database user also referred to as a traditional user is an individual who is associated with passwords and schemas. For instance, an application or a person that logs onto the database uses a database user (schema) as well as a password. Database users are, therefore, able to create heavyweight sessions to the schemas that they are associated with.

An application user, on the other hand, can be an autonomous application process or a person that accesses information or data in the database. Unlike database users, application users do not own database schemas. However, they are able to create application sessions to databases via the middle tier. They are also able to create heavyweight database sessions via direct connection to the database.

3. Explain the difference between database roles and application roles.

A database role is traditionally imagined to be a set of database privileges that applications, database users, or other database roles are granted. Database roles serve as intermediaries that map database privileges to database applications and users.

On the other hand, an application user is often regarded as a set of application-define privileges associated with it and it is only granted to application users or to other application roles. An application role uses an access control list (ACL) instead of a database grant. It is the ACL that maps the application privileges to roles or users. Application roles cannot be granted to database roles.

5. What are the differences between client/server and web-based applications?

Client/server application follows two-tier architecture (front-end and backend.) while a web-based application follows three-tier architecture (Browser, web server, and DB server). Web-based applications are mainly used in internet areas while client/server applications are in intranet areas.

A client/server application involves one server and one or many client applications while a web-based application is a type of client/server application hosted on the web server and then accessed over the internet. It is often difficult to test scripting problems in client/server applications whereas is it easier for web-based applications to test scripting problems in. Changes regarding scripting cannot reflect in client/server applications however in web-based applications it reflects at the moment only.

7. Give an example of why data encryption is needed and when you would use encryption.

Data encryption is the coding of information to make it unreadable by anyone not authorized other than those individuals who possess special knowledge to change the information back to a readable form. Data encryption is needed security to protect confidential data or information that anyone else is not supposed to access.

Encryption is used by businesses to protect corporate secrets; individuals use it to guard against identity theft by protecting personal information, and governments often use it to secure their classified information. It can also be used to ensure or facilitate secret communication, particularly for governments, individuals, and businesses. Encryption is used when very confidential data is in transit, those being transferred through networks. It is also used when very confidential data is at rest (stored) such as files on storage devices and computers.

10. Which layer of the OSI model implements security in a Web application?

The OSL model layer that implements security in a web application is definitely the application layer (layer seven) since it is the main interface that permits user-application interaction. Everything that takes place in this layer is application-specific. The application layer provides application services for e-mail, file transfer as well as other network software services making it the best layer to implement security.