ACLB and ABB

Adaptive Client Load Balancing (ACLB) and Adaptive Band Balancing (ABB) improve Wi-Fi performance by steering clients to APs with higher available capacity and guiding clients to different radio bands for better load balancing, respectively.

Feature Overview

ACLB enhances the existing Client Load Balancing (CLB) system by incorporating throughput-based capacity metrics alongside traditional station-count load metrics. IEEE 802.11k allows clients to request and receive information about neighboring APs. By knowing the status of neighboring APs, clients can make more informed decisions, aiding in balancing the load. IEEE 802.11v enables APs to communicate directly with clients about the best APs to connect to, facilitating smoother and more efficient handoffs. This helps prevent any single AP from becoming overloaded by dynamically guiding clients to less congested APs.

When enabled, ACLB works as follows:

  • Identify High-Capacity APs: Detect APs with higher available capacity within the RF neighborhood.
  • Select Target Clients: Determine which clients must be moved to less loaded, higher-capacity APs using 11k/v protocols and AP-to-AP communication.
  • Client Switch Request: Prompt target clients to switch to the identified APs, which are ranked by priority.
  • Client Roaming: Clients select a target AP and roam to it, ensuring balanced load and optimal service quality across the network.

Band balancing supports client load balancing by guiding clients to different radio bands (2.4GHz, 5GHz, and 6GHz, if available). Band balancing was originally designed to operate only at the time of client association, but the Adaptive Band Balancing (ABB) enhancement ensures load balancing by band occurs dynamically through the duration of the client connection.

Requirements

The ACLB and ABB features have no special hardware or software requirements for feature enablement or usage.

Considerations

Consider the following with regards to the ACLB enhancement:

  • ACLB does not support non-802.11v-capable stations.
  • ACLB does not steer stations that move away from the AP within 270 seconds of association, preventing unnecessary redirection of the station, especially if the station’s movement away from the AP is temporary or if the signal strength remains robust despite the increased distance from the AP.
  • ACLB estimates the available capacity of neighboring APs if they do not publish this information.

Best Practices

  • Ensure all APs are running firmware that supports ACLB and IEEE 802.11k/v protocols.
  • Place APs to maximize coverage and minimize signal overlap, creating distinct RF neighborhoods for effective load balancing.
  • Enable regular background scanning (bgscan) on APs to maintain accurate data on neighboring APs and their available capacities.

Prerequisites

The following prerequisites facilitate optimal load balancing in your network:

  • Ensure all APs and controllers run firmware that supports ACLB (Unleashed 200.8 and later releases) and IEEE 802.11k/v protocols.
  • Deploy a robust network infrastructure with sufficient bandwidth and low latency to support real-time load balancing.
  • Strategically place APs to maximize coverage and create distinct RF neighborhoods, minimizing signal overlap and interference.
Parent topic: Client Load Balancing