An RF (Radio Frequency) survey report is crucial for WLAN design as it provides detailed information about the current wireless environment, including signal strengths, interference sources, coverage gaps, and the effectiveness of the existing WLAN infrastructure. For a company like 'No-Stair Inc.' that is planning to refresh its WLAN across a global footprint, understanding the current RF conditions in each location is essential. This information helps in designing a WLAN infrastructure that can meet the specific needs of different areas within the locations, such as the retail area and warehouse, ensuring optimal coverage, performance, and user experience. An RF survey report would allow the designer to make informed decisions regarding the placement of new access points, the selection of appropriate antennas, and the configuration of WLAN parameters to improve coverage and capacity while minimizing interference.

ACME Retail is in the planning stages of upgrading their current PBX system to a VoIP system, as indicated by their intention to move away from the existing PBX system later in the year. This upgrade is part of their overall network infrastructure overhaul to incorporate modern bestpractices. Additionally, the company is facing challenges with their current inventory control system, particularly with Zebra barcode scanners having signal issues throughout the stores, making monthly inventory processes difficult. Improving the inventory control system to achieve almost real-time inventory for their online service is a critical aspect of their growth and cost-cutting strategy, hence it's in the planning stage as well.

Based on the requirements provided by "Don't Buy at Us," the updated design needs to accommodate 25GbE uplinks and a minimum of 7 stacks of 48-port Aruba switches for the EMEA-DISTR. Option C is the most suitable based on best practices, as it proposes:

• A core configuration consisting of two Aruba 8360-12C in VSX for the collapsed core with ISL of 2x100GbE DAC, which will provide robust core networking with high-speed interconnects, suitable for the demands of a regional distribution center and headquarters.
• Aggregation with two stacks, each with 2 Aruba 8360-12C in VSX (ISL 2x100GbE DAC), accommodating the uplink capacity requirements.
• Access stacks with a total of 17 stacks of Aruba 6300F 48-port 1GbE Class 4 PoE with 4-port SFP56 (each stack has 4 members, VSF with 50GbE VSF links, 2 x 25GbE uplinks per stack), which exceeds the minimum requirement of 7 stacks and provides the necessary uplink bandwidth.

This configuration supports the 25GbE uplink speeds, satisfies the required number of switch stacks for the EMEA distribution center, and is compatible with the existing 25GbE-certified fiber infrastructure at HQ2 and EMEA-DISTR.

When floor plans are not available for site surveys or simulations, the best alternative source to use is the fire escape plan (Option D). Fire escape plans are typically available in most buildings and provide a simplified layout of the premises, including walls, doors, and sometimes the location of permanent fixtures. While not as detailed as architectural floor plans, fire escape plans can offer enough information for initial site survey estimations and RF planning. They allow network designers to understand the basic layout and potential RF obstacles or coverage areas, making them a practical tool for preliminary wireless network planning and simulations in the absence of more detailed floor plans.

Mode Conditioning Patch Cables (MCPs) are used in situations where long wavelength laser transceivers, such as the 1000Base-LX, are deployed over multimode fiber types like the 62.5/125 µm. The 1000Base-LX transceivers are designed primarily for use with single-mode fiber, but they can operate over multimode fiber using an MCP. The MCP is necessary because the core size of multimode fiber (62.5/125 µm) is significantly larger than that of single-mode fiber, which can lead to modal dispersion when a single-mode laser signal enters the multimode fiber. This dispersion can degrade the signal quality over longer distances. The MCP mitigates this issue by aligning the single-mode laser output from the transceiver to a specific launch point in the multimode fiber, thus minimizing dispersion and allowing for effective data transmission over distances up to 500 meters.

In the scenario described, the most significant issue with the core switch selection, according to Aruba Campus Access learning resources, is answer A: "The core switch will not support the 25GbE downlinks to the distribution switches." This is a critical consideration because the bandwidth capabilities between the core and distribution layers significantly impact the overall network performance and scalability. If the core switch cannot support 25GbE downlinks, it may create a bottleneck, preventing the distribution switches from operating at their full capacity and affecting the performance of connected devices and applications. Ensuring the core switch has the necessary port speeds and densities to support the intended design and traffic patterns is crucial in network design, as emphasized in Aruba's documentation on campus network architectures.

For a solution design incorporating Aruba OS10-based access points with the specified requirements, including Wi-Fi 6E support, tunneled traffic, application visibility, rogue AP detection, live upgrades, Air Slice, Cloud Guest Authentication, and AI insights, the necessary licenses are AP Foundation (Option A) and AP Advanced (Option C). The AP Foundation license provides basic connectivity and network access control features essential for establishing a Wi-Fi network. The AP Advanced license adds advanced capabilities such as application visibility and control, enhanced security features like rogue AP detection, and performance optimization features like Air Slice. These licenses together ensure the access points can deliver the full range of required functionalities, from reliable basic connectivity to sophisticated network management and security, making them suitable for a comprehensive and high-performing wireless network solution.