Abstract: Disclosed is a method and apparatus for testing segmentation and reassembly functionalities of a communication network signalling node. A test signal is provided to a message transfer part ("MTP") of a signalling node. The test signal includes a first user portion, and the first user portion includes test parameters. The MTP and a connected signaling connection control part ("SCCP") then process the test signal and provide the first user portion to an application layer of signaling node. After receiving the first user portion, the application layer generates a second user portion based on the test parameters. The second user portion is then provided to an SCCP to be tested. The SCCP to be tested the performs segmentation operation on the second user portion, thereby creating a plurality of test signal segments.