Protocol testing and software testing cannot be treated as two streams, protocol testing is indeed a subdomain of software testing . Though the testing types (functional, performance, NEGATIVE etc) are same, the TOOLS USED and the method of testing are different.

When a tester is testing a router or a SWITCH, he /she is infact testing a program which is part of the operating system of that DEVICE. So protocol testing is not the testing of physical device , but it is testing of a software in it.

Protocol testing and software testing cannot be treated as two streams, protocol testing is indeed a subdomain of software testing . Though the testing types (functional, performance, negative etc) are same, the tools used and the method of testing are different.

When a tester is testing a router or a switch, he /she is infact testing a program which is part of the operating system of that device. So protocol testing is not the testing of physical device , but it is testing of a software in it.