All four statements accurately describe the characteristics and trade-offs of wireless traffic forwarding modes in a Huawei fabric network.

Tunnel Forwarding: All wireless traffic is encapsulated and sent to a central Wireless Access Controller (WAC). This centralizes traffic, enabling unified policy enforcement and management (A). However, this creates a traffic detour, concentrating the forwarding load on the WAC and potentially creating a performance bottleneck (C).

Direct Forwarding: Wireless traffic is forwarded directly from the Access Point (AP) to the wired network. This avoids the WAC bottleneck and encapsulation overhead, resulting in higher forwarding efficiency (B). However, when a user roams between APs connected to different edge switches, their network entry point changes, which can necessitate re-authentication and IP address reallocation, thus degrading the roaming experience (D).

All the provided options are correct statements describing the attributes of tunnel and direct forwarding modes within a fabric wireless network.

1. Huawei CloudCampus Solution 3.1.T Solution Description, Section: "WLAN Service Basics" -> "Forwarding Mode". This document details the two forwarding modes. It explicitly states that tunnel forwarding "facilitates centralized user management and security control" (supports A) but "all service traffic is forwarded through the WAC, which imposes high-performance requirements on the WAC" (supports C). It also describes direct forwarding as having "high forwarding efficiency" (supports B) but notes that for inter-AC or inter-group roaming, "the user IP address needs to be re-obtained, affecting user experience" (supports D).

2. Huawei iMaster NCE-Campus V300R021C00 Product Documentation, Section: "WLAN Service Configuration" -> "Forwarding Mode". The documentation explains that in direct forwarding, "service data packets are not encapsulated by CAPWAP tunnels and forwarded by the WAC. Instead, they are directly forwarded by the access device," which improves efficiency (supports B). Conversely, it describes tunnel forwarding as a model where the WAC "centrally forwards service data packets of all APs," which facilitates centralized control but increases WAC pressure (supports A and C). The implications for roaming in direct mode are also discussed as a key consideration (supports D).