Case study description

This case study uses a typical conformance tester for a network element of GSM. GSM is the 2nd generation network for mobile communications, which is deployed in Europe and in a lot of other countries. An SMLC is a GSM network element needed in location based services. It operates under control of a BSC and provides positioning data to the BSC. To compute the positioning information it uses the services of one or several PDEs. The SMLC is taking the role of the client, the PDEs act as servers. Several TCP connections between the SMLC and the PDEs can be opened simultaneously.

The SUT in this scenario is the SMLC, the test system takes the roles of one or more PDEs. Because the test system is acting as a server, it has to accept TCP connections from the SUT. It has even to accept TCP connection on several ports with different port numbers and also several connections simultaneously for the same server port.

Two properties of the SMLC are tested with this test system:

• The first property is the correct encoding of the RPP messages, i.e. test whether messages are encoded and decoded correctly by the system under test. For this purposes there are test cases available both to send correctly encoded as well as incorrectly encoded messages. By sending incorrectly encoded messages the robustness of the decoder in the system under test can be tested.
• The second property is conformance to the standard, i.e. it is checked whether the system under test implements the correct behaviour. For this purpose a small set of example test cases is available.