What is good teaching of computer networks?

In this paper it is argued, based on theoretical as well as empirical grounds, that a university teacher in computer networks can improve students´ learning by being aware of the different ways in which the students understand the concepts that he or she teaches. The distinct, qualitatively different, ways, in which students understand the network protocol TCP (transmission control protocol), have been revealed in a research project, performed with a phenomenographic qualitative approach. The perceptions of TCP held among the students have been evaluated, based on situational appropriateness and richness. The results indicate that all the ways in which TCP is understood in the group are relevant during different phases of a software development project, and with different tasks at hand. Thus, a teacher should encourage students to understand what he or she teaches in different ways and should help them to choose in a relevant way between these perceptions. These results are also related to current research into students´ learning, which clearly demonstrate that teaching, based on results of this type, promotes better understanding.