Match each OSI layer to its description.
Drag a concept onto its matching description — or click a concept then click the description.
Data Link layer; handles MAC addressing and framing
Network layer; handles routing and logical addressing
Transport layer; handles reliable delivery and flow control
Application layer; provides network services to applications
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Physical Layer: Transmits raw bits over a physical medium.
The correct matches are: Physical layer transmits raw bits, Network layer routes with logical addressing, and Application layer supports user applications. Common confusions involve swapping the roles of Data Link and Transport layers.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Physical Layer: Transmits raw bits over a physical medium.
Why this is correct
The Physical layer is correctly described as transmitting raw bits over a physical medium. This foundational layer is responsible for the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between devices. It defines how data bits are converted into signals (e.g., electrical pulses, light pulses, radio waves) and transmitted across cables, fiber optics, or wireless channels, ensuring the raw binary data reaches its destination.
Network Layer: Routes packets using logical addressing.
Why this is correct
The Network layer is accurately described as routing packets using logical addressing. This crucial layer is responsible for determining the best path for data packets to travel across different networks, utilizing logical addresses like IP addresses for identification. It handles the forwarding of packets from source to destination, enabling inter-network communication and ensuring data reaches the correct subnet or host, even across complex network topologies.
Application Layer: Provides network services to end-user applications.
Why this is correct
The Application layer is correctly described as providing network services to end-user applications. This top layer of the OSI model serves as the interface between the user's software applications and the underlying network services. It enables applications such as web browsers, email clients, and file transfer programs to access network resources and communicate with remote hosts, facilitating user interaction with network functionalities.
Data Link Layer: Provides end-to-end communication and error recovery.
Why it's wrong here
This description is incorrect for the Data Link layer. While the Data Link layer does provide error detection and sometimes recovery within a *local* segment, "end-to-end communication and error recovery" is a primary function of the Transport layer. The Data Link layer primarily focuses on reliable data transfer between adjacent network nodes (node-to-node) over a physical link, handling framing, physical addressing (MAC addresses), and media access control for local delivery.
Transport Layer: Provides reliable node-to-node communication.
Why it's wrong here
This description is incorrect for the Transport layer. "Reliable node-to-node communication" is a characteristic more aligned with the Data Link layer, which ensures error-free transmission between directly connected devices. The Transport layer, however, is responsible for providing reliable *end-to-end* communication between processes running on different hosts, managing segmentation, reassembly, flow control, and error recovery for the entire communication session, often using port numbers.
Quick reference
| Layer | Name | PDU | Key Protocols / Devices |
|---|---|---|---|
| 7 | Application | Data | HTTP, HTTPS, DNS, SMTP, FTP, SSH |
| 6 | Presentation | Data | TLS / SSL, JPEG, ASCII encoding |
| 5 | Session | Data | NetBIOS, RPC, SIP |
| 4 | Transport | Segment / Datagram | TCP, UDP |
| 3 | Network | Packet | IP, ICMP, OSPF — Routers |
| 2 | Data Link | Frame | Ethernet, Wi-Fi, PPP — Switches, Bridges |
| 1 | Physical | Bits | Cables, NICs, Hubs, Repeaters |
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This N10-009 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the N10-009 exam.