Protocol has its use in applications such as computer networking, telecommunications etc. Computer network protocols are Ethernet, IP, TCP, UDP, HTTP etc. Telecommunication protocols are SIP, H.323, Ss7, MGCP etc.
Protocol Testing is the study of testing telecom protocols. Protocols are tested by understanding their specifications. Software Testing study involves studying various testing methodologies required for testing the software. Protocol testing involves applying these software testing methodologies to test the implementation of protocol using special tools meant for that.