Wi-Fi 7’s Multi-Link Operation (MLO) is rewriting the rules of wireless connectivity, promising blazing speeds and rock-solid reliability. But can it handle the chaos of 256 clients in a high-density environment?

In this blog, we’ll walk you through building, testing, and optimizing a 256-client MLO setup using WiCheck—a blueprint for pushing Wi-Fi 7 to its limits and beyond.

This blog explores MLO connectivity, performance, stability, scalability, and efficient traffic handling under high traffic.

Why Build a 256 Client MLO Environment?

Testing 256 clients isn’t just a flex—it’s a necessity. It validates scalability for real-world hotspots like stadiums or smart offices, stress-tests AP stability, and sets a benchmark for future-proof networks. With WiCheck, you’ll see exactly how far you can push this tech.

Test Environment Overview

To evaluate the stability and performance of Access Points by sequentially increasing the number of MLO (Multi-Link Operation) MLMR (Multi-Link Multi-Radio) clients up to 256, the following setup was configured:

• • 4 x Scale Generator 7: Each device is capable of emulating 64 MLMR (Multi-Link Multi-Radio) clients, totaling 256 clients. It supports a 4×4 NSS (Number of Spatial Streams) configuration with an operating bandwidth of 160MHz in the 5GHz band and 320MHz in the 6GHz band. MLO connections are established using 5GHz + 6GHz links.
  • Access Point (Device Under Test – DUT): The DUT is an Access Point supporting MLO MLMR connections across all three bands—2.4GHz, 5GHz, and 6GHz—with MLO enabled on all bands and configured with a 4×4 NSS.
  • Configuration: SSID set to “WiCheck_AP” with SAE (Simultaneous Authentication of Equals) security.

Scenario 1: Stress-Testing AP Connection Capacity with 256 MLO MLMR Clients

In this initial stress test, our primary objective was to push the Access Point (DUT) to its connection capacity limits. By simulating 256 MLO MLMR clients, we aimed to determine the point at which the AP’s performance would begin to degrade or fail.

Scale Generator 7 and AP Connection

• • To simulate a high-density environment, four Scale Generator 7 devices were employed. Each Scale Generator 7 was configured to emulate 64 MLO MLMR clients, utilizing dual-band connections (5GHz + 6GHz). This resulted in a total of 256 simulated MLO MLMR clients.
  • The Device Under Test (DUT), a Wi-Fi 7 MLO Access Point, was configured to enable full MLO functionality across its 2.4GHz, 5GHz, and 6GHz radios, allowing it to establish MLO connections with the simulated clients.
  • The 256 clients were not connected simultaneously. Instead, they were introduced incrementally to observe the AP’s behavior under increasing load.

Observations and Results During testing:-

AP Failure and Client Disconnection

During the stress test, the Access Point (AP) exhibited stable performance while supporting up to 128 MLO clients. However, as the client count increased above 128, a software exception occurred. This exception triggered an automatic reboot of the AP, resulting in the immediate disconnection of all connected clients.

Scenario 2: Evaluating AP Uplink Traffic Handling with 256 Clients Across Dual APs

Building upon the findings of the initial stress test, which revealed a connection limitation for a single AP at 128 MLO clients, we designed a second scenario to evaluate uplink traffic handling with 256 clients distributed across two Access Points (APs). The 256 simulated MLO MLMR clients were evenly distributed between the two APs, with each AP handling 128 clients.

1. Scale Generator 7 and AP Connection

a. Used 2 WiFi7 MLO AP’s which are configured with the MLO functionality to connect the MLO MLMR clients.

b. Clients were incrementally connected, starting at 64 per AP1 and scaling to 128. and the same is released for AP2.

2. Traffic Setup

a. Iperf3_TCP_UL traffic was configured for 180 seconds across all Scale Generator 7s.

b. The traffic was started simultaneously on all four Scale Generator 7s.

Observations and Results During testing:-

1. Traffic Load Analysis

• • The traffic executed successfully for entire of 180 seconds on the 4 Scale Generator 7.
  • No immediate failures were noticed during the active traffic phase.

2. Performance Metrics Analyzed

• • The following key performance indicators were the focal points of this study:
  • Aggregate Throughput (TCP Uplink): Measured the total throughput in both uplink (UL) direction as the number of 802.11be clients increased.
  • The Below graph mentions the Aggregate Throughput over different clients.

Scenario 3: Evaluating AP Downlink Traffic Handling with 256 Clients Across Dual APs

Building upon the findings of the initial stress test, which revealed a connection limitation for a single AP at 128 MLO clients, we designed a second scenario to evaluate Downlink traffic handling with 256 clients distributed across two Access Points (APs). The 256 simulated MLO MLMR clients were evenly distributed between the two APs, with each AP handling 128 clients.

1. Scale Generator 7 and AP Connection

a. Used 2 WiFi7 MLO AP’s which are configured with the MLO functionality to connect the MLO MLMR clients.

b. Clients were incrementally connected, starting at 64 per AP1 and scaling to 128. and the same is released for AP2.

2. Traffic Setup

a. Iperf3_TCP_DL traffic was configured for 180 seconds across all Scale Generators.

b. The traffic was started simultaneously on all four Scale Generators.

Observations and Results During testing:-

1. Traffic Load Analysis

• • The traffic executed successfully for the entire 180 seconds on the 4 Scale Generator 7.
  • No immediate failures were noticed during the active traffic phase.

2. Performance Metrics Analyzed

• • The following key performance indicators were the focal points of this study:
  • Aggregate Throughput (TCP Downlink): Measured the total throughput in both Downlink (DL) direction as the number of 802.11be clients increased.
  • The Below graph mentions the Aggregate Throughput over different clients.

Key Observations from 256-Client MLO Testing with WiCheck

The study evaluated Wi-Fi 7’s Multi-Link Operation (MLO) performance under high client loads using WiCheck.

1. AP Stability & Scalability

• • The Access Point (AP) remained stable up to 128 MLO clients, but beyond this, a software exception led to an AP reboot, disconnecting all clients.

2. Uplink Traffic Performance

• • With two APs handling 256 clients, Iperf3 TCP Uplink traffic ran successfully for 180 seconds without failures.
  • Aggregate throughput was analyzed as clients increased.

3. Downlink Traffic Performance

• • Iperf3 TCP Downlink traffic executed smoothly with no immediate failures.
  • Throughput performance was measured across different client loads.

Potential Next Steps

• • Extended endurance testing (running traffic for a longer duration) to check for any degradation over time.
  • Varying the traffic load (high-load and low-load conditions) to observe network behavior under different stress levels.
  • Analyzing packet loss, latency, and jitter to get detailed insights into network performance.

The results indicate a stable and functional WiFi7 network setup, but future tests should focus on scalability, endurance, performance under varying conditions, and real-world application scenarios. This will help fine-tune deployments for large-scale, high-density environments while ensuring consistent, high-performance connectivity.