Software Engineering

1. Software engineering is the establishment and use of sound engineering principles in order to obtain economically software that is reliable and works efficiently on real machines.

2. (IEEE) Software Engineering: (1) The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software; that is, the application of engineering to software (2) the study of approaches as in (1).

3. Software Engineering is an engineering discipline which is concerned with all aspects of software production from the early stages of system specification through to maintaining the system after it has gone into use.

Objectives of database

• The general objective is to make information access easy, quick, inexpensive and flexible for the user.
• Several objectives: 

1. Controlled redundancy 
2. Ease of learning and use 
3. Data independence 
4. More information at low cost 
5. Accuracy and integrity. 
6. Recovery from failure 
7. Privacy and security 
8. Performance. 

Database Design

§Database is recognized as a standard of MIS. In a database environment, common data are available and used by several users.

§Instead of each program managing its own data, data across applications are shared by authorized users  with the database software managing data as an entity.

§An application program requests data through DBMS.

Database

A database is a collection of interrelated data stored with minimum redundancy.

Routing Protocol Vs Routing Algorithm

Routing Protocol	Routing  Algorithm
A routing protocol uses software and routing algorithms to determine optimal network data transfer and communication paths between network nodes.	A Routing Algorithm is a method for determining the routing of packets in a node.
Routing protocols facilitate router communication and overall network topology understanding.	A Routing Algorithm is not facilitate router communication and overall network topology understanding.
The protocol  should not lead to a consistent routing, that is to say without loop	The algorithm should lead to a consistent routing, that is to say without loop
For each node of a network, the protocol does not determines a routing table,	For each node of a network, the algorithm determines a routing table, which in each destination, matches an output line

Routing Algorithm

A Routing Algorithm is a method for determining the routing of packets in a node. For each node of a network, the algorithm determines a routing table, which in each destination, matches an output line. The algorithm should lead to a consistent routing, that is to say without loop. This means that you should not route a packet a node to another node that could send back the package.

Classification of Routing Protocols

Classification of routing protocols

Although there are many types of routing protocols, three major classes are in widespread use on IP networks:

• Interior gateway protocols type 1, link-state routing protocols, such as OSPF and IS-IS

type 2, distance-vector routing protocols, such as Routing Information Protocol, RIPv2, IGRP.

• Exterior gateway protocols are routing protocols used on the Internet for exchanging routing information between Autonomous Systems, such as Border Gateway Protocol (BGP), Path Vector Routing Protocol. Exterior gateway protocols should not be confused with Exterior Gateway Protocol (EGP), an obsolete routing protocol.