Reusability and Effective Test Automation in Telecommunication System Testing

1. Reusability and Effective Test Automation in Telecommunication System Testing Mikael Mattas Supervisor: Professor Sven-Gustav HäggmanInstructor: B.Sc. Jouni Haara

2. Contents • Research Problem and Objectives • Testing • Automation of Testing • Tellabs 8600 Managed Edge System • Testing Pratices Used for the Tellabs 8600 Managed Edge System • Automating System Testing of the Tellabs 8600 Managed Edge System • Conclusions and Recommendations • Further Research

3. Research Problem and Objectives • Design and implement an effective solution for automation of system testing of the Tellabs 8600 Managed Edge System • Analyze the automation praxices used in integration testing to check what could be reused in automation of system testing

4. Testing • The process of exercising software to verify that it satisfies specified requirements and to detect errors • Important part of a telecommunication system development project • Dissatisfied customers if the system does not work as expected • Costly to fix errors after the system has been shipped to the customer • Testing Levels • Unit/Module testing • Integration testing • System testing • Acceptance testing

5. Testing • V-model • Frequently used software development model

6. Automation of Testing • Writing software to test other software • Make testing more effective • Able to run existing tests easily and quickly on a new version of software • Better use of resources • Testers more motivated and have time to do other tasks like planning • Machines and workspace can be used during nights and weekends • Perform tests which would be difficult or impossible to do manually, e.g. simulation of many users • Consistency and repeatability of tests, the tests will be repeated exactly every time

7. Automation of Testing • Also a lot of pitfalls and limitations • Poor testing practice • Better to improve the effectiveness of testing first than to improve the efficiency of poor testing • Maintenance of automated tests • Automated tests should be designed so they are easy to maintain and can be re-run successfully on a new version of software • Trying to automate too much • It is not possible or desirable to automate all testing activties. One should not automate tests that are run only rarely, tests without predictable results, tests where the result is easily verified by a human, but is difficult if not impossible to automate, tests where the software is very unstable and usability tests.

8. Automation of Testing • Bad test automation • Capture/replay method • Scripts generated through recording have hard coded data that makes it difficult to maintain the scripts • Good test automation • Based on reusable modules and one-point system maintenance • Script reuse means elimination of duplication, speeding up implementation of new tests, and saving on maintenance costs • Automated tests vs. automated testing • Also pre- and post-processing tasks surrounding the execution of a test case have to be automated if unattended testing during nights and weekends is wanted

9. Tellabs 8600 Managed Edge System • IP/MPLS based system used by service providers to build access networks for providing Intranet, Extranet, Internet access and corporate voice services to business customers • Connections based on layer 2 or layer 3 MPLS VPNs • Consisting of different network elements (NEs) and a network management system (NMS) with a graphical user interface (GUI)

10. Testing Pratices Used for the Tellabs 8600 Managed Edge System • Enhanced V-model based on internal releases • Implementation testing (unit/module testing), integration testing, and system testing • Implementation testing and integration testing is divided into separate network element (NE) testing and network management system (NMS) testing, whereas system testing combines both parts

11. Testing Pratices Used for the Tellabs 8600 Managed Edge System • No automated test cases in system testing, but some automation used in NMS integration testing and NE integration testing • NMS integration testing uses a functional testing tool called WinRunner for automation of NMS GUI operations • NMS integration testing uses so called user functions to build up a test case. A user function is reusable and can e.g. handle an NMS window. User functions are built up by so called reusable system functions, which are used to carry out actions common for many applications within the NMS, e.g. clicking different types of buttons.

12. Testing Pratices Used for the Tellabs 8600 Managed Edge System • The structure of a test case in NMS integration testing

13. Testing Pratices Used for the Tellabs 8600 Managed Edge System • NE integration testing uses an in-house built test automation environment called TestNET and Tcl-scripts to configure network elements and measurement equipment • A typical test case in system testing consists of both configuring NEs with help of the NMSfor setting up a VPN and configuring measurement equipment for generating the data to be sent through the VPN to test it → techniques used in both NMS integration testing and NE integration testing are needed in automation of system testing → need for integration of WinRunner and TestNET

14. Automating System Testing of the Tellabs 8600 Managed Edge System • Automation of GUI operations in the NMS • A basic VPN test case was chosen. The VPN was tried to be built by using the same structure and functions used in NMS integration testing to check whether the structure could be used also in system testing. Purpose also to find shortages and improvement needs. • Good structure in general, could be reused. But for improved maintainability there was a need for more reusability than just reusable user and system functions → the concept of higher level functions was introduced. By moving logical sequences of user function calls within the module files into higher level functions, a new level of reusable functions was reached.

15. Automating System Testing of the Tellabs 8600 Managed Edge System • The suggested structure of a test case in system testing

16. Automating System Testing of the Tellabs 8600 Managed Edge System • Automating the configuration of the measurement equipment • New measurment equipment (N2X) was procured for system testing purposes → no scripts could be reused from NE integration testing • Generic Tcl procedures were developed and TestNET was used for execution of Tcl scripts. NE integration testing can also utilize the procedures if they start using N2X.

17. Automating System Testing of the Tellabs 8600 Managed Edge System • Integration of the techniques • Communication channel needed in order to command measurement equipment from WinRunner with TestNET • A TCP/IP socket was created between WinRunner and TestNET, and plain-text commands and responses were sent between the parties

18. Conclusions and Recommendations • Evaluation of the implemented structure for automated test cases • The integration of the techniques was successful and the first automated system test case could be created • By using higher level functions it was found that it is easy and does not take a long time to create new test cases • There was no need for copy-paste actions as in the structure used in NMS integration testing • Maintenance costs were minimized, so that if something had changed in the GUI one had to make changes only in one place to update all test cases • Easy to run the test cases also in different environments • Structure recommended to be used in subsequent automation of system testing

19. Further Research • Before more test cases are automated, it has to be studied whether software is stable enough • Automate pre- and post-processing tasks so that a set of tests can be run unattended during nights and weekends • Integration of the WinRunner scripts with the used test management tool, TestDirector