To enable fast and reliable delivery of mobile text messages (SMS), special bidirectional protocols are often used. Measuring the achieved throughput and involved latency is however non-trivial, due to the complexity of these protocols. Modifying an existing system would incur too much of a risk, so instead a new tool was created to analyse the log files containing information about this traffic in a black-box fashion. When the produced raw data was converted into graphs, they gave new insights into the behaviour of both the protocols and the remote systems involved.