GTP prime (GTP') is a protocol for carrying charging data from the Charging Data Function (CDF) to the Charging Gateway Function (CGF). The protocol is used in the Ga interface. The GTP Prime Test Suite has been designed to act as malicious enpoint which sends exceptional requests/responses to the tested entity. The test suite acts as either CDF or CGF depending on the tested endpoint. The GTP Prime Test Suite can be used to relay CDR data to the CGF. This enables a test setup, where test-cases created by some other test case source, for example Universal ASN.1 BER Fuzzer, can be relayed to the SUT over the GTP prime protocol. The GTP Prime Test Suite itself does not test CDR layer.