When sending a GET request, Application Layer generates HTTP payload -> Transport Layer wraps TCP header (ports) -> Network Layer wraps IP header (IP addresses) -> Data Link Layer wraps Ethernet frame (MAC addresses) -> Physical Layer transmits binary electrical signals.
HTTP, HTTPS, DNS, SMTP generate payload data.
TCP/UDP adds source/destination ports and sequence numbers (PDU = Segment).
IP protocol adds source/destination IP addresses and routing headers (PDU = Packet).
Ethernet protocol adds source/destination MAC addresses and CRC checksum (PDU = Frame).
| Feature / Dimension | OSI Model (7 Layers) | TCP/IP Model (4 Layers) |
|---|---|---|
| Layers | Physical, Data Link, Network, Transport, Session, Presentation, Application | Network Access, Internet, Transport, Application |
| Origin | ISO theoretical standard reference model | US DoD practical internet protocol implementation |
Detailed answers, interviewer pro tips, key takeaway summaries, and code examples formulated for technical rounds.
✅ Correction: MAC addresses are permanent physical hardware addresses for local network hops; IP addresses are logical addresses used for global internet routing.
Layered architectures for network communications.
Network services directly accessible to user software applications.