TCP/IP model alignment: which TCP/IP layer corresponds functionally to the OSI Transport layer?

Introduction / Context:
When translating concepts between the 7-layer OSI model and the 4-layer TCP/IP model, it helps to know which layers roughly correspond. The OSI Transport layer (Layer 4) handles end-to-end transport services such as reliability and flow control.

Given Data / Assumptions:

• OSI Transport layer provides TCP/UDP-like services.
• TCP/IP’s four layers are Application, Host-to-Host (or Transport), Internet, and Network Access.

Concept / Approach:
Identify which TCP/IP layer provides end-to-end transport. That is the Host-to-Host (sometimes called Transport) layer, where TCP and UDP operate. The Internet layer maps to OSI Network (routing), and Network Access maps to OSI Data Link/Physical.

Step-by-Step Solution:

Verification / Alternative check:
Any reference diagram shows TCP and UDP at the Host-to-Host layer, clearly mapping to OSI Transport.

Why Other Options Are Wrong:
Application: Maps to OSI Layers 5–7 combined.
Internet: Maps to OSI Network (Layer 3).
Network Access: Maps to OSI Layers 1–2.

Common Pitfalls:
Confusing “Internet” with “Transport” due to TCP’s name; remember TCP and UDP are not in the Internet layer.

Final Answer:
Host-to-Host