The Media Gateway Control Protocol (MGCP) is a signaling and call control communications protocol used in voice over IP (VoIP) telecommunication systems. It implements the media gateway control protocol architecture for controlling media gateways on Internet Protocol (IP) networks connected to the public switched telephone network (PSTN). MGCP is a master/slave protocol that allows a call control device such as a Call Agent to take control of a specific port on a media gateway. In MGCP context media gateway controller is referred to as call agent. This has the advantage of centralized gateway administration and provides for largely scalable IP Telephony solutions. The distributed system is composed of a call agent, at least one media gateway (MG) that performs the conversion of media signals between circuits and packets switched networks, and at least one signaling gateway (SG) when connected to the PSTN. With this protocol, a CallManager knows and controls the state of each port on the gateway. It allows complete control of the dial plan from CallManager, and gives CallManager per-port control of connections to the public switched telephone network (PSTN) and so forth. This is implemented with the use of a series of plain-text commands sent over User Datagram Protocol (UDP) port 2427 between the CallManager and the gateway. MGCP is used widely in the modern Internet. This test suite can be used to test MGCP server implementations for security flaws and robustness problems.