Contents

1 The network protocol stack

• Protocols define the rules that must follow the network entities to communicate.
• In Internet, all network applications must use at least the IP
• Different protocols provide different services.
• Each protocol encapsulate the header + payload (data) that a higher protocol delivers.

2 Level 2: Data-link layer protocols

3 Level 3: IP protocols

4 Level 4: Transport layer protocols

5 Level 5: Application layer protocols