DESIGN AND MANAGEMENT OF

COMPUTER NETWORKS

CSK DEPARTMENT OF INFORMATION TECHNOLOGY

OXFORD ENGINEERING COLLEGE - TRICHY

UNIT - II

CHARACTERIZING BEHAVIOUR

(uses,works,represents,classification)

It representing how users and applications use the network. In order to develop and understand their requirements.

It consistsEstimates of user session duration.The number of active sessions.Data sizes(word sizes range 16 bit, 128 bit)-

size of data.Detailed models(Description) of user and

application behavior.

CHARACTERIZING BEHAVIOUR

A session Is a semi-permanent interactive information / ordialogue / orconversation inter change.

Interaction between a computer and the user .Ex: Login History(login /logout timestamps)

LAST ACCESS.

SESSION

Session duration:Average amount of time that visitors spend on

the site each time they visit.Ex:  Total duration of all sessions (in seconds)

Timestamps : (OCT 27.10.2014 10:00:10:10 AM)

Estimates of user session duration

When a user arrives to a webpage, a session variable is created for the user .(temp)All websites that allow you to show the number

of visitors use database.(webpage history)(visitors count)Ex:

Session Expiration: Internet Login.TIMESTAMP(11:11:11 - 27.10.2014)

The number of active sessions

Data sizes(size of the Bytes/bits)(Storage)- max /min

Detailed models of user and application behavior.

Types of the behavior:USER BehaviorAPPLICATION BehaviorNETWORK Behavior

Definition:Simulation modeling is the process of creating

and analyzing a digital prototype of a physical model(equipment) to predict its performance in the real world. 

Digital Prototyping gives conceptual design, Engineering, Manufacturing, Departments the ability to virtually explore a complete product before it’s built.Example: AutoCAD, CAM, matLABAutodesk Simulation Mechanical

MODELING AND SIMULATION

Physical Prototyping is the process of making a physical representation of an idea.

Digital Prototyping:Digital Prototyping gives conceptual design,

engineering, manufacturing, and sales and marketing departments the ability to virtually explore a complete product 

Physical Prototyping

Simulation modeling is used to help designers and engineers understand whether, under what conditions, and in which ways a part could fail and what loads it can withstand.

Developing models or simulations of user, application, and network behavior useful in predicting, determining or estimating requirements and data flows.

Models can range from Easy, Simplistic, Complex and time consuming.

It is not a ‘physical implementation’

MODELING AND SIMULATION

Modeling and simulation are useful throughout the ANALYSIS PROCESS for characterizing user, application, and existing network behaviors.

Simulation modeling allows designers and engineers to avoid repeated building of multiple physical prototypes.

To analyze designs for new or existing parts. Before creating the physical prototype, users can virtually investigate many digital prototypes. Using the technique, they can:

Optimize geometry for weight and strength(Geometry is all about shapes and their properties. )

Select materials that meet weight, strength, and budget requirements Simulate part failure and identify the loading conditions that cause them Assess extreme environmental conditions or loads not easily tested on physical

prototypes, such as earthquake shock load Verify hand calculations. Validate the likely safety and survival of a physical prototype before testing's

MODELING AND SIMULATION

SIMULATION OF NETWORK PERFORMANCE BEHAVIOR

Utilization performance:

Delay performance:

Capacity performance:

It is useful to understand how users of the system will apply applications.Simple usage patterns can include user work

times and durations.Each application the total number of users.The frequency that a user is expected to have

an application session running.(number of sessions per user, per day).

How long an average application session will last(order of minutes)

No . of simultaneous user sessions for that application.

USER BEHAVIOR

It is useful to determine the behavior of application sessions.

It is used to modify performance requirements.

To achieve a better estimate of performance levels you will need for your network.Characterizing application behaviorData sizes that the application will be

processing / passing / communication across the network.

Frequency and time duration for data to be passed across the network.

APPLICATION BEHAVIOR

Traffic flow characteristics get for applications: Flow directions (ex: from client to server) Requirements for multicasting / broadcasting / unicast(walki-

talki).(communication service)

Multicast is communication between a single sender and multiple receivers on a network.Broadcasting is the distribution of audio and/or video content via any electronic mass communications medium(fm)

Benefits of user and application behavior: Mission – critical(levels of importance) Rate – critical(transfer data rate) Real time(implementation) Interactive(how application works with user) High performance()

THANK YOU

Developing RMA requirements:MTBCF – mission time between critical failureMTBF- mission time between failureMTTR – mean time to repairUptime / downtime

Developing DELAY requirements:Interaction Delay(INTD)Human Response Time(HRT)Network Propagation Delay(NPD)End – To – End delayRountrip DelayDelay variations

Forthcoming topics so far

Estimates Data Rates: PDR – peak data rate.MDR – Minimum data rate.SDR – sustained data rate.

Developing supplement : Operational suitabilitySupportabilityRMAWorkforce

Developing CAPACITY requirements