Using semicontrollable interfaces in testing army communications protocols: application to MIL-STD 188-220B

Testing army communications protocols is considered for a testing environment where the tester has limited degrees of controllability on applying inputs to an implementation under test. The inputs fall into three categories: directly controllable, semicontrollable, or uncontrollable. A graph conversion algorithm is presented to utilize the semicontrollable inputs, thereby increasing the number of testable transitions. The research was motivated while generating tests for MIL-STD 188-220B. The number of testable transitions for 188-220B Class A-Type 1 Datalink Service module is approximately 200 without utilizing semicontrollable inputs. These 200 account for only 30% of the transitions defined in the protocol specification. The presented methodology makes it possible to increase the number of testable transitions to over 700. Combined with our previous work on testing protocols with timing constraints, the methodology allows us to generate tests free of interruptions due to timeouts, and covering more than 95% of the defined transitions in 188-220B's Type 1 Datalink Layer.