So one must be careful to choose a PL that has the proper level of abstraction for the lesson to be taught and the model to be molded. If you want them to understand it in terms of bits and bytes and machine instructions, C and it's ilk is the way to go. If you want them to understand it as a set of libraries that can be slowly dissected, then Python and similar languages can be the way to go.
Either way, both are really just models for the more abstract thought of network transport.