Protocol testing means to test the functionality of the

node(piece of software) which should compliance to some

standard message flow. For this one should take a

tester(Testing Unit) which should send standard messages to

the node(Item under test). Above all tester mentioned are

good but according to me K1297-G20(Tektronics)is the best

tester.

Advantages

1) Many standard Protocol are supported by this tester

2) One can add just new protocol supports easily

3) With introduction of G-20 its interface is really good,

one can easily learn.

Disadvantages

1) Load can't be tested with this, as this tester is windows

based with low processing capabilities

2) It is little bit costly as it give license per link per

protocol base

3) Support too have some issues