the essence of the internet idea

Computer Systems A Programmer's Perspective Second Edition

 

Of course, we are glossing over many difficult issues here. What if different net-

works have different maximum frame sizes? How do routers know where to for-

ward frames? How are routers informed when the network topology changes?

What if a packet gets lost? Nonetheless, our example captures the essence of the

internet idea, and encapsulation is the key.