Essential Network Protocols for Distributed Systems

Choose network protocols by the communication guarantees the application needs: message semantics, ordered delivery, response time, and behavior after a connection fails. This lesson separates HTTP at the application layer from TCP and UDP at the transport layer.

Separate processes can fail or become unreachable independently. A successful network send does not establish that a remote service completed the requested business operation. Keep that distinction in mind when designing APIs and retries.

Start with the path from a client to a server in the diagram below.