Computer Networks, 5th Edition

9. Applications

Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.

–Winston Churchill

Problem

Applications Need Their Own Protocols

We started this book by talking about application programs—everything from web browsers to videoconferencing tools—that people want to run over computer networks. In the intervening chapters, we have developed, one building block at a time, the networking infrastructure needed to make such applications possible. We have now come full circle, back to network applications. These applications are part network protocol (in the sense that they exchange messages with their peers on other machines) and part traditional application program (in the sense that ...