On a large campus network, inter-WAC roaming must be avoided where possible to ensure the roaming experience.

The statement is correct. In a large campus WLAN, the roaming experience is a critical performance indicator, especially for real-time services like voice and video. Intra-WAC (also known as Intra-AC) roaming, where a client moves between Access Points (APs) managed by the same Wireless Access Controller (WAC), is significantly faster and more seamless than inter-WAC roaming.

Intra-WAC roaming involves a simple and rapid update of the client's forwarding path within a single controller that already holds the client's security and session context. In contrast, inter-WAC roaming requires a more complex and time-consuming process involving signaling and context transfer between two separate controllers. This inter-controller communication introduces additional latency, which can lead to packet loss and service interruption during the handover. Therefore, a fundamental best practice in WLAN design for large campuses is to plan the network topology and AP-to-WAC assignments in a way that minimizes the frequency of inter-WAC roaming events.

This is a True/False question. The alternative, "False," is incorrect because it would imply that inter-WAC roaming is either equivalent or preferable to intra-WAC roaming in terms of user experience, or that avoiding it is not a design consideration. Official documentation and network design principles clearly establish that inter-WAC roaming introduces higher latency and complexity. While the feature is necessary for mobility across very large, segmented networks, it is not the preferred roaming method from a performance standpoint, and its occurrence should be minimized through careful network planning.

1. Huawei, "WLAN Roaming Technology White Paper": This document details the technical processes for different types of roaming. In the sections describing "Inter-AC Roaming," it explains the additional steps required, such as the exchange of mobility messages between the home AC and foreign AC and the establishment of a data tunnel. These steps inherently introduce more delay compared to the streamlined "Intra-AC Roaming" process, which is handled entirely within one controller. The design implication is to favor intra-AC roaming for better performance.

2. Huawei, "CloudCampus Solution WLAN Network Planning Guide": Network planning guides for large-scale solutions like CloudCampus emphasize design principles for optimal performance. A key principle is the logical grouping of APs under a single AC to match physical user roaming domains (e.g., a building or a floor). The explicit goal of this planning is to ensure most roaming events are intra-AC, thereby providing a low-latency, seamless user experience and reserving the more complex inter-AC roaming for less frequent, wide-area movements.

3. Huawei, "WLAN AC Configuration Guide - WLAN Service - Roaming Configuration": In the configuration guides for setting up mobility groups (a prerequisite for inter-AC roaming), the documentation describes the mechanism for controllers to share user information. The existence of this complex configuration requirement itself points to the overhead involved. The guides implicitly support the design goal of limiting this overhead by recommending that APs in a contiguous coverage area be managed by the same AC.