Which TCP/IP layer provides end-to-end communication between processes on different hosts?

• A. Application layer
• B. Transport layer
• C. Internet layer
• D. Link layer

Answer: (B)

End-to-end communication between processes on different hosts is provided by the Transport layer. This layer sits between the applications and the network, using port numbers to multiplex multiple conversations from different processes on the same host. It breaks data into segments, and it can offer reliable delivery with TCP (including sequencing, error recovery, and flow control) or a simpler, best-effort service with UDP. By handling end-to-end transport, the Transport layer enables data from a specific process on one machine to reach the corresponding process on another machine, across the network. The Internet layer handles routing and addressing between hosts, while the Link layer deals with local network transmission.