Detecting OAM

1
Detecting OAMP design defects using a feature
interaction approach
- Internet telephoney
service focus
Team 9 5004692 2273994 3484095 3028498 5007299
3411946 3474249
2
Purpose

• Introduce Feature Interaction (FI) and OAMP
• Provide methods handling FI
• Provide methods detecing FI in OAMP

3
Outline

• Concepts of FI and OAMP
• Current Research Motivation
• Methods handling FI under OAMp
• Case Study
• Conclusions

4
Feature Interaction

• Defination
• Services running at the same time create
  undesired alters affecting behaviors

5
Feature Interaction

• Example
• Original Call Screening (OCS) allows users create
  a blacklist to block calls
• Call Forwarding Unconditional (CFU) allows users
  to redirect call
• FI Problems
• If user A has OCS with user C and user B has CFU
  to C
• when A calls B, FI problem occurs

6
OAMP

• Operation
• Adminstration
• Maintance
• Provision

7
OAMP

• Functions of OAMP
• Operations Coordinating between other aspects
• Adminstration Designing network, processing
  orders, assigning address, tracking usages and
  accounting
• Maintance Diagnosing and repairing errors
• Provisioning Installing equipment, setting
  paremeters,verfying service, updating and
  de-installing

8
Current Reserach Motivation

• Foucs on grey-colour components
• Few studies on addressing problems
• TMN frames (FCAPS) standarize OAMP implentation
  in PTSN
• No more interest in OAMP FI because OAMP not
  directly influence end-user's usage of service

9
Methods Handling FI

• Handling FI Problems
• Period Design Time
• Components
• 1. Detecting
• 2. Resolving

10
Detecting Resolving FI

• 1. Detecting FI
• Service operation logic need to be modelled in a
  suitable formalism
• Detecting alogrithm should be applied
• 2. Resolving FI
• Design need to be reviewed

11
P509 FI Detection Method

• Period 1995-1996
• Area European Companies
• Object consistent and cost-effective FI solution
  covering whole service lifecycle
• Missionanalyzing all solutions and modelling
  approaches reported by specialized literature so
  far

12
P509 FI Detection Method

• Defining four FI detection models
• 1. Concept-based
• 2. Goal-based
• 3. Feature invocation graph-based
• 4. Pre/post-condition-based
• NOTE
• Only first detection applied to OAMP features!

13
P509 FI Detection Method

• Details
• 1.Modelling a service as a sequence of
  manipulations performed on concepts
• 2.Manipulation actions could be to read or to
  modify
• 3.Concepts are addresses, call state, charging
  records, etc
• 4.Comparing two service models.
• Example
• An interaction detected
• service reads a concept that is modified by the
  other service

14
P509 FI Detection Method

• Applied to previous example

15
OAMP Modelling Feature Relationship

• Changes made to P509
• 1.FeaturesSystem concept and entites OAMP
  services
• built on
• 2. Relationship
• 2.1 Usenot affect data or processing
• 2.2 Modify affect data or processing

16
FI Detection Procedure

• 1.General Princples
• Comparison of couples of ERs
• 2.Two Types
• (1)UM A uses C, B modifies C
• (2)MM A modifies C, B modifies C
• 3.Check
• (1) UM B's modify alter A's logic?
• (2)MM C accept modify?
• 4.Results
• (1)Not undersirable, ignored.
• (2)Need to review

17
Case Study

• Internet Telephoney Softswitch
• Input136 ERs
• Algorithm

18
Case Study
Input and Results
19
FI Flow Chart - UM Interaction
20
FI Flow Chart - UM Interaction
21
FI Flow Chart - MM Interaction
22
FI Flow Chart - MM Interaction
23
FI Flow Chart - MM Interaction
24
FI Flow Chart - MM Interaction
25
FI Flow Chart - MM Interaction
26
FI Flow Chart - MM Interaction
27
FI Flow Chart - MM Interaction
28
Conclusions

• Feature Interaction (FI)could be avoided in
  design time
• Implementing FI problem approach
• (1)Modelling Feature relationship
• 1.UM
• 2.MM
• (2)Check each one through compairing
• (3)Reporting results
• (4)Modifying Design

29

• Thank you for Listening!