What is the OSI model and its layers?
Theme: Networking Fundamentals Role: Network Engineer Function: Technology
Interview Question for Network Engineer: See sample answers, motivations & red flags for this common interview question. About Network Engineer: Designs and maintains computer networks. This role falls within the Technology function of a firm. See other interview questions & further information for this role here
Sample Answer
Example response for question delving into Networking Fundamentals with the key points that need to be covered in an effective response. Customize this to your own experience with concrete examples and evidence
- Overview of the OSI Model: The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a communication system into seven distinct layers
- Layer 1: Physical Layer: The Physical Layer is responsible for transmitting raw bit streams over physical media, such as cables or wireless signals. It deals with electrical, mechanical, and physical aspects of the network
- Layer 2: Data Link Layer: The Data Link Layer provides error-free transmission of data frames between adjacent network nodes. It ensures reliable and efficient communication by handling framing, error detection, and flow control
- Layer 3: Network Layer: The Network Layer enables end-to-end packet delivery across multiple networks. It handles logical addressing, routing, and fragmentation of data packets
- Layer 4: Transport Layer: The Transport Layer ensures reliable and transparent data transfer between end systems. It provides end-to-end error recovery, flow control, and multiplexing/demultiplexing of data streams
- Layer 5: Session Layer: The Session Layer establishes, manages, and terminates communication sessions between applications. It handles session establishment, synchronization, and checkpointing
- Layer 6: Presentation Layer: The Presentation Layer deals with the syntax and semantics of the information exchanged between applications. It handles data encryption, compression, and protocol conversion
- Layer 7: Application Layer: The Application Layer provides services directly to the end-user applications. It includes protocols for file transfer, email, remote login, and other high-level functions
- Summary: The OSI model defines a layered approach to network communication, allowing for standardized and interoperable systems. Each layer has specific functions and protocols that contribute to the overall network functionality
Underlying Motivations
What the Interviewer is trying to find out about you and your experiences through this question
- Technical Knowledge: Assessing the candidate's understanding of the OSI model and its layers
- Problem-solving skills: Evaluating the candidate's ability to troubleshoot network issues based on the OSI model
- Communication skills: Determining the candidate's ability to explain complex technical concepts in a clear and concise manner
- Experience & expertise: Assessing the candidate's level of experience and expertise in network engineering
Potential Minefields
How to avoid some common minefields when answering this question in order to not raise any red flags
- Lack of knowledge: Not being able to provide a clear and accurate explanation of the OSI model and its layers
- Confusion or inconsistency: Mixing up the layers or providing incorrect information about their functions
- Overcomplicating the answer: Using technical jargon or going into unnecessary detail that may indicate a lack of understanding
- Omitting important layers: Leaving out or not mentioning all seven layers of the OSI model
- Inability to relate to real-world examples: Not being able to explain how the layers of the OSI model are applied in practical network scenarios
- Lack of understanding of layer interactions: Failing to explain how the layers interact with each other and the purpose of each layer in the overall network communication process