Which model serves as a guide for troubleshooting and designing networks?

The OSI Model serves as a comprehensive framework for troubleshooting and designing networks due to its structured approach to networking. Comprising seven distinct layers, the OSI Model delineates the functions and responsibilities at each layer, from physical transmission of data to application-level interactions. This layered architecture helps network engineers and administrators systematically diagnose issues and design networks.

By breaking down network processes into manageable segments, the OSI Model allows for targeted troubleshooting, where a problem can be isolated to a specific layer, such as the transport or application layer. This clarity greatly simplifies the process of identifying and resolving networking issues.

While the TCP/IP Model is also relevant in networking, it has a more streamlined approach with fewer layers, which may not offer the same level of granularity for troubleshooting as the OSI Model. Other options, like the Network Layer Model and Communication Model, do not provide the comprehensive multi-layer framework that is vital for systematic network design and troubleshooting.