This document discusses network flows and flow analysis. It defines flows as sequences of packets sent from a source to a destination. Flow analysis describes and characterizes traffic flows by identifying where they occur and what performance they require. Flows can be individual, representing a single application, or composite, representing the combination of requirements from multiple applications sharing a network. Flow models help categorize flows based on environment type. Prioritizing flows determines which get more resources based on importance factors.

1. UNIT - III

2.  OBJECTIVES:
 This chapter introduces flows and
flow concepts, data sources and
data sinks, and flow models will help
us to identify, size, and describe
flows.

3.  FLOWS:
 Flows also known as network flows
or traffic flows or data flows.
 It provides the traffic movement in
the network.
 A sequence of packets sent from a
particular source to a particular
(unicast or multicast) destination.

4.  FLOWS ANALYSIS:
 Flow analysis is the process of describing
/characterizing traffic flows for a
network.
 Where they are likely 2take place/occur.
 What levels of performance they will
require.

5. BENEFITS:
 Provides hierarchy (arrangement) levels.
 In choosing interconnection strategies
such as (switching, routing and hybrid)
mechanisms.
 Flows are represented as Unidirectional
or Bidirectional performance.
 Bidirectional :
 Unidirectional:

6.  It is represented as single and
double sided arrows.
 Most flows are Bi-Directional
arrows.
 Flows are important in analysis,
architecture and design process.

7.  TRAFFIC FLOW:
 Traffic flow is the study of
interactions between traffic
control devices and minimal
traffic congestion(packet loss)
problems.

8.  Flow attributes, such as
 Source/Destination address,
 Type of information,
 PORT numbers like,
▪ 21 FTP (File Transfer Protocol)
▪ 25 SMTP (Send Mail Transfer Protocol)
▪ 68 DHCP (Dynamic Host Control Protocol)
▪ 80 HTTP (Hyper-Text Transfer Protocol)
▪ 161 SNMP (Simple Network Management Protocol)
▪ 8080 HTTP

11. Composite
flows
Individual
flows
Flows

12.  It is an One-Way delay/application
requirement for a single session.
 Requirements are left with individual flow
and not consolidated with other
requirements.
 Uni-directional (UPSTREAM).
 Single applications of flows that share a
common link, path or network.
 It has guaranteed requirements.

14.  The combination of requirements
from multiple applications of
individual flows that share a
common link, path or network.
 Bi-directional (UPSTREAM/DOWNSTREAM).
 Most flows in a network are
composites.

16.  It requires high or guaranteed
performance that are operate
/control the architecture and design.
 Example:
 Mission critical(MTBF,MTBCF)
 Rate critical(PDR,SDR)
 Real critical.

17.  An activity, device, service or system
whose failure or problems which
interrupt an event will cause a
failure in business operations.
 For example, an online business's
mission critical.

18.  Mission critical refers to any factor
of a system like,
 equipment,
 process,
 procedure,
 Software
 whose failure will result in the
failure of business operations.

19.  Critical rate is an attribute of your
character that determines how
often you make a critical attack.
 For example,
 if your critical rate is 40% then on
average 4 out of every 10 attacks
will be a critical attack.

20.  Focusing on particular application
 Developing a profile
 Choosing the top N applications

21.  Focusing on an application
 Application group
 Device / functions.

22.  Profile or template can be developed
for applications.
 Each flow fits the profile identified
with profile tag.
 Profiles are used to simplify
information.

23.  Top 5 Applications
 Web browsing
 E-mail
 File Transfer
 Word processing
 DB transaction
 The purpose, determine which
application represent the most
important requirements for the
network.

24.  Data sources:
 It is used to generate the data flow.
 Represented as circle with
cross(star/asterisk).
 Two dimensional plane, arrow coming
out.
 Data sinks:
 It is used to terminate the data flow.

25.  The group of flows publicly display the
consistent behavior characteristics is
called as ‘flow models’.
 Useful to identify and categorize flows
in an
 Environment
 peer-to-peer
 client-server
 hierarchical client-server and
 distributed computing.

26.  FLOW PRIORITIZATION
 Flows can be prioritized according to
importance, based on the characteristics.
 To determine which flows get the most
resources or which flows get resources first.
 Some prioritizations include:
▪ Business objectives
▪ Political objectives
▪ RMA and QoS
▪ Security Requirements
▪ The numbers of users, applications and devices.

27.  It is a mechanism to combine these
performance requirements (capacity,
delay and RMA).
 To describe the optimal composite
performance for that flow or group
of flows.

28.  Example:
 Building and device locations
▪ Requirement analysis
▪ Flow models
▪ Flow map

29. THANK YOU