Detecting OAM&P design defects using a feature interaction approach - Internet telephoney service focus Team 9+ 5004692 2273994 3484095 3028498 5007299

Detecting OAM&P design defects using a feature interaction approach

- Internet telephoney service focu

s

Team 9+5004692 2273994 3484095 3028498 5007299 3411946 3474249

Purpose

• Introduce Feature Interaction (FI) and OAM&P• Provide methods handling FI • Provide methods detecing FI in OAM&P

Outline

• Concepts of FI and OAM&P

• Current Research Motivation

• Methods handling FI under OAM&p

• Case Study

• Conclusions

Feature Interaction

Defination: Services running at the same time create undesired alt

ers affecting behaviors

Feature Interaction

Example:• Original Call Screening (OCS) allows users create a blacklist to bloc

k 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

OAM&P

• Operation

• Adminstration

• Maintance

• Provision

OAM&P

Functions of OAM&P• Operations: Coordinating between other aspects• Adminstration: Designing network, processing orders, as

signing address, tracking usages and accounting• Maintance: Diagnosing and repairing errors• Provisioning: Installing equipment, setting paremeters,ve

rfying service, updating and de-installing

Current Reserach Motivation

• Foucs on grey-colour components• Few studies on addressing problem

s• TMN frames (FCAPS) standarize O

AM&P implentation in PTSN• No more interest in OAM&P FI beca

use OAM&P not directly influence end-user's usage of service

Methods Handling FI

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

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

P509 FI Detection Method

• Period: 1995-1996• Area: European Companies• Object: consistent and cost-effective FI solution covering w

hole service lifecycle• Mission:analyzing all solutions and modelling approaches r

eported by specialized literature so far


Defining four FI detection models1. Concept-based2. Goal-based3. Feature invocation graph‐based4. Pre/post‐condition‐based

NOTE:Only first detection applied to OAM&P features!


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


Applied to previous example:

OAM&P Modelling Feature Relationship

Changes made to P509:

1.Features:System concept and entites OAM&P services

built on

2. Relationship

2.1 Use:not affect data or processing

2.2 Modify: affect data or processing

FI Detection Procedure

1.General Princples:Comparison of couples of ERs2.Two Types:(1)UM: A uses C, B modifies C(2)MM: A modifies C, B modifies C3.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

Case Study

Internet Telephoney Softswitch

Input:136 ERs

Algorithm:

Case Study

Input and Results:

FI Flow Chart - UM Interaction

FI Flow Chart - UM Interaction

FI Flow Chart - MM Interaction







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

Thank you for Listening!

Documents

Detecting OAM&P design defects using a feature interaction approach - Internet telephoney service focus Team 9+ 5004692 2273994 3484095 3028498 5007299