Method and device for monitoring operation of communication protocol procedure

摘要

This document discloses a method, apparatus, and computer program for automatically detecting unallowed continuation of a communication protocol procedure in a communication device. The method comprises in a test tool: marking an invalid input applied to the communication device in a sequence of operations of the communication protocol procedure (200); marking, with a sequence marker, a location that should not be reached in the sequence of operations of the communication protocol procedure as a result of the invalid input (202); and upon detecting that the communication protocol procedure has reached the location marked with the sequence marker (204), outputting an indication that the communication device operates in an unallowed manner (206).