The employment of TTCN-3 for testing the Application Server in the IMS network.

Damian Zolich, TTCN-3 User Conference 2011Ericpol Telecom Sp. z o.o. 7 – 9 June 2011 - Bled, Slovenia damian.zolich@ericpol.comTel.: +48 663 426 716

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Agenda

IntroductionStep 1 Without TTCN-3Step 2 New test environment with TTCN-3Step 3 Make testing easyStep 4 Our future

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Our environment in numbers

• About 7000 test cases• Up to 80 components in one test case• About 45 users• 930 files• 1,5 million code lines • Support for 7 different protocols• 11 interfaces

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Step 1 Without TTCN-3

• Only one protocol (SIP)• Very basic scenarios• Simple environment • Simple matching mechanism

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Simple environment

Caller

Application

Server

Callee

Traffic Generator

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New challenges

• New traffic generator (H.248)• More and more complex scenarios• New protocols in the near future• More and more pressure on matching mechanism

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Caller

Application

Server

Callee

Traffic Generator

SIP

MRFP

Traffic Generator

H.248

Second protocol

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Test team problems

1. Preparation for the test execution 2. Exchanging information between traffic

generators3. No flexibility4. Poor matching mechanism 5. Code reuse6. Message synchronisation7. Verification of correct message sequence8. Timers

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Solution

We need something completely different.

So let’s try TTCN-3

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Step 2 New test environment with TTCN-3

Ro (online charging)

Rf (offline charging)

IMS AS

MGW

P-CSCF

S-CSCF

I-CSCF

HSS

MGCF

CSCF

PSTN/PLMN

other SIPnetworkCSCF

SIP

SIP

SIP

Charging

Diameter

MRFP

H.248

Provisioning

LDAP

Voice &Video mail

SIPCx

CM,PM

Muta

ISC

LDAP

Mp

Audio & VideoAnnouncementsAudio & Video Conference

SBG

SIP

SIP NNIor H.323

Sh

Diameter/TCP

SLF

DhDiameter/TCP

CAI3G/XCAP

Dx

Px App

Px

MRFC

Mr SIP

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New challenges

Test environment which enables:• Simulation of nodes around the Application Server • Support of all required interfaces• Support of all required protocols • Support of advance matching mechanism• Coordination between interfaces

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Function Test Environment

Sh

(Diameter)

Rf

(Diameter)

MP

(H.248)

CCF

OperatorCM

MRFPMRFP1

SLF

Dh

(Diameter)

MTAS

ISC(SIP)

OperatorPM

Ro

(Diameter)

ECF

S-CSCF

HSS

HSS

TTCN-3

CAI3G/Ut (XCAP)

Muta

(LDAP)

S-CSCF

PIPETestport

OperatorPM

Provisioning

MRFPMRFP2

IMS AS

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Basic call setup vs. Test simulation

OriginatingCSCF

OriginatingIMS AS

Primary CCF

SIP: INVITE

SIP: INVITE

SIP: 180 Ringing

SIP: 180 Ringing

SIP: 200 OK

SIP: 200 OK

Alice

SIP: INVITE

SIP: 180 Ringing

SIP: 200 OK

SIP: ACKSIP: ACK

SIP: ACK

TerminatingCSCF

Terminating network

SIP: INVITE

SIP: 180 Ringing

SIP: 200 OK

SIP: ACK

DIAMETER: Accounting-Request Start

DIAMETER: Accounting-Answer Start

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New test team problems

1. Testing is time consuming2. Development of test cases difficult to learn3. Lots of code to write for one test case4. Test execution quite complex

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Solution

We need a good test

Framework and Automation

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Step 3 Make testing easy

TTCN-3 function library & API• Creation and initialization of test components, routing of messages and verification of message content

Test automation scripts• Run before and after the TC call flow.• Ensures test environment integrity and checks for problems caused by

TC execution.

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Directory Structure

Sh/Dh Rf Ro Mp MrMa Isc

Test Object – Service I Test Object – Service II

Test module

Private functions

Test module

Private functions

Test module

…

Framework

ScriptsDIAMETER H248DNS SIP Test automation

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Messages exchange on ports between the SUT and the Framework components (defaults used)

Outgoing IMS AS

PortIMS AS Incoming IMS AS

Port

5060 ISC1

SIP_DISPATCHER_CT 5061ISC2

ISC_SESSION_CTISC1

ISC_SESSION_CTISC2

1 .Invite

2 .Invite

3 .Invite

4 .Invite

5 .200 OK

6 .200 OK7 .200 OK

8 .200 OK

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CSCF

(SIP dispatcher)

Framework component overview

IMS AS

Caller (ISC Session)

CCF dispatcher

Non-SessionDispatchersuses list of keys todifferientiate sessions

Non session related data

Rf Session 1

HSS dispatcher

Non-Session

Sh session X

Sh session 1

Rf Session XCallee (ISC Session)

Sip caller and callee are together a SIP session

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Framework benefits

• Higher abstraction level for writing TCs• More readable/understandable test cases

written in a consistent style• Complex and extensive common verification

details are handled transparently and automatically

• Simplifies TC maintenance and development• New checks can be added automatically to

existing TCs via the framework

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Framework benefits

• Majority of TC’s automated• Full automated regression test• Flexibility in test case creation• User friendly

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Examples of automated test activities

Pre execution activity:• cleaning environment• checking environment • run external applications (e.g. wireshark)Post execution activity• collecting all logs into one archive file• monitor for hanging processes, memory leaks &

system crashes

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Step 4 Our future

• Environment very flexible to test new features required by customers

• Smart way of regression testing• More testing in shorter time

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Damian Zolich, TTCN-3 User Conference 2011Ericpol Telecom Sp. z o.o. 7 – 9 June 2011 - Bled, Slovenia damian.zolich@ericpol.comTel.: +48 663 426 716

Thank you