Which level of backbone connects Main Cross-connects to Intermediate Cross-connects?

The first-level backbone is responsible for connecting Main Cross-connects to Intermediate Cross-connects. This backbone serves as the primary pathway for telecommunications and data transport between different areas within a facility. In a typical structured cabling system, the first-level backbone links critical infrastructure components, facilitating efficient communication and ensuring that data can flow seamlessly across the network.

The definition and function of the first-level backbone clarify its role in a building's telecommunications layout. It orchestrates the main connections, supports the overall architecture of networking, and plays a vital part in maintaining the integrity of the data systems involved.

In contrast, other options represent different levels of backbone networks or components that do not specifically fulfill the function of establishing the direct connection between the Main and Intermediate Cross-connects. The second-level backbone connects Intermediate Cross-connects to Horizontal Cross-connects, while the third-level backbone generally pertains to connections beyond the internal structure of a building, such as between buildings. The Building Distribution Backbone refers more broadly to the comprehensive distribution architecture within a building rather than to a specific connection pathway. Thus, the first-level backbone is the appropriate choice for the connection described in the question.