UNIT - ONE

INTRODUCTION

Network analysis process begin with requirement analysis.

This consists of Identifying, Gathering, Deriving and Understanding

system requirements and their characteristics.

REQUIREMENT ANALAYSIS

Definition: also called system engineering, software

engineering, requirement engineering. It is the process of determining user

expectations for a new or modified product.

It involves frequent communication with clients to servers.

Requirements analysis are descriptions about the network funciton and network performance.

helps the designer to better understand the network behaviors such as (network technology , services, topology design).

Provides software designer with a network model of: system information(hw & sw) functions Behaviors

Model can be translated to data, architectural, and component-level designs.

REQUIREMENT ANALAYSIS

TYPES OF REQUIREMENT ANLAYSIS

Functional requirements: input/output processing. error handling.

Non-functional requirements: Physical environment (equipment locations,

multiple sites, etc.). Interfaces (shared boundary xchng info etc.). User & human factors (who are the users, their

skill level etc.).

Non-functional requirements (continued): Performance (how well is system functioning). Resources (data, information, etc.). Security (encryption, biometrics, firewall). Quality assurance ( ensuring the quality of a

service or product etc.).

OBJECTIVES

Discover the boundaries/limitations of the new system/user.

Detect and resolve conflicts between the user and the system requirements.

REQUIREMENTS AND FEATURES

Each network should have, as a minimum, a set of core requirements.

Requirements are categorized during the requirements analysis process.

Requirements that are determined to be necessary for the success of the network project are termed core or fundamental requirements.

THE NEED FOR REQUIREMENT ANALYSIS

Requirements analysis helps the designer to better understand the network being built.

This results in several payoffs(objectives): choices of network technologies and services. The ability to apply technology and topology candidates to

networks. Networks and elements properly sized to users and

applications. A better understanding of where and how to apply services

in the network.

REQUIREMENTS ORGANIZATION:

User Application Device Network Other

USER REQUIREMENTS

User requirements comprise the set of requirements that is gathered or derived from user input and represent what is needed by users.

Typically, when gathering requirements, everyone involved with that network is considered a potential user

TYPES OF USER REQUIREMENTS

TYPES OF USER REQUIREMENTS

USER SERVICE REQUIREMENTS

Timeliness: (correctness requirement) Data actually changes. All views of the data are updated.

Interactivity: (Across the many fields). human-computer interaction, communication with industrial design. 

Reliability: (consistency" or "repeatability") the ability of a system or component to perform

its required functions under stated conditions for a specified period of time.

Supportability: Maintenance, repair and operations(MRO) Involves administrative, scheduled

maintenance, and supervision action. Future growth:

Growth potential is an organization's future ability to generate larger profits, expand its workforce and ramp up its production.

USER SERVICE REQUIREMENTS

Adaptability:  to adapt itself efficiently and fast to changed circumstances.

Quality: quality for your network projects. Security:  protection from harm, un-authorized. Affordability : Customers will ultimately decide

which tools, equipment they buy/use based on requirements.

Functionality:  to identify product features and aspect of what a product, such as a software application or computing device, can do for a user.

PERFORMANCE REQUIREMENTS

Delay: designed to operate effectively over extreme distances.

Reliability: consistency process Capacity:complex measurement of

max.amount of data that may be transferred between network location over a link or network path.

USER REQUIREMENTS

In general, the system should adapt to users and their environments.

User requirements are the least technical and are also the most subjective.

Our intent is to use these basic requirements as a start toward developing more objective and technical requirements in the other components.

APPLICATION REQUIREMENTS

Application requirements are requirements that are determined from application information, experience, or testing, and represent what is needed by applications.

Application requirements are more technical than user requirements but may still be subjective.

TYPES OF APPLICATION REQUIREMENTS

APPLICATION TYPES

Based on service and performance requirements, applications were type as:

mission-critical RMA rate-critical capacity, or real-time/interactive delay

These application types are described by their requirements and service metrics.

APPLICATION TYPES

A loss of any part of RMA in such applications may be serious or disastrous, such as:

Loss of revenue or customers Unrecoverable information or situation Loss of sensitive data Loss of life

In terms of capacity, there are some applications that require a predictable, bounded, or high degree of capacity include voice and non-buffered video.

APPLICATION TYPES

From an application service perspective, optimizing the total, end-to-end, or round-trip delay is usually the most important things.

APPLICATIONS GROUPS

It is often useful to group applications with similar performance characteristics.

Application can be identified using the requirements analysis process.

Telemetry Applications Visualization Applications Distributed Applications Web, Access and Use Applications Operations, Administration and Maintenance

APPLICATION LOCATIONS

It is often useful to determine where application applies in an environment.

This will help in mapping traffic flows during the flow analysis process.

Application types, their performance requirements, their locations, and application groups form the interface between the application component and the rest of the system.