Cisco 9115AXI Concurrent Devices

[Mr. San]

Hello,

I would like to know, how many client can connect to Cisco 9115AXI AP at the same time?

Or how can I select the AP base on user?

Thank you.

[Flavio Miranda]

Hi @Mr. San 

 Theorically:

"Wi-Fi 6, with better coordination of transit time to and from devices, will also bring about a reduction in latency and a
greater reliability allowing for hundreds of devices per access point. This allows for IoT devices to be reliably deployed at
scale. And an overall improved user experience will be seen as well, as 802.11ax will improve device battery life of devices
such as smartphones, tablets and IoT when compared to prior standards. For more details about 802.11ax please check
Cisco’s Technical Whitepaper on 802.11ax"

[jagan.chowdam]

There is no hard limit on the number clients supported by an AP. It all depends on various factors such as RF environment, WLC config, Client capabilities etc. 

If you want to understand AP - client performance, I suggest looking at Miercom performance test reports such as https://miercom.com/wp-content/uploads/2021/03/Miercom-Report-Cisco-AP9100-Competitive-Performance-DR201007H.pdf

Again the numbers you see may not match real world deployment. 

CJ

[Dustin Anderson]

This is for Meraki, but they use the same Cisco APs, so expect similar.

• Wi-Fi 6 (MR28/36/44/45/46/46E/55/56/76/78/86): 512 clients per radio = 1024 clients max per AP
• I've also seen some with 256/radio, but if you are hitting these limits you have more issues to look into.

Unless you run the old airOS, then the limit is 200/AP.

[JPavonM]

Supported numbers on any AP model from any vendor is just only marketing.

As @jagan.chowdam said, there is a dependency from multiple factors on the maximum number of client stations an AP can support without impacting quality-of-experience (QoE), not AP performance. And adding more, those test done by Miercom are not real-world scenarios as they do not content with nearby APs using the same RF space, so that is an ideal scenario where your ofice is isolated from the outer world, which is not impossible by using certain wall materials.

This is what you need to attend to:

1. Coexistence, which is the number of stations (APs and clients) in the neighbourhood using the same channel.
2. Supportability, or which 802.11 standards the connected clients do support (by connected clients I mean all stations using the same channel in the vicinity), if they are all from the same 802.11ax or they coexist with legacy standards, so clients won't benefit from all Wi-Fi 6 features.
3. Load, meaning the amount of traffic been delivered to/from the stations using the same channel (not AP).
4. Sensitivity, or how the ongoing transmissions can deal with congestion due to the previous bullets, specially due to delayed transmissions (if that traffic is for near real-time applications such as conferencing or audio, then they maybe impacted if there would be high congestion)
5. Configuration of RF parameters, such as channel bonding, or basic and supported data rates. Supporting low data rates you allow stations to move apart from AP so maybe shifting to lower rates and modulation schemes that could lower QoE.
6. And most important hint, do not confuse link speed (negotiated data rate) with real throughput as this use to be around 70% at most from the data rate, and this is only on a scenario where the is only one station, as adding 'n' transmitting stations reduces the real throughtput 'n' times.

You can take these numbers as an approach to better know when QoE will start to drop to a less acceptable status:

Client count: 32
Channel Utilization: 45%
RSSI: -68 dBm
SNR: 20 dB

Regarding AP performance, using C9115 or C9120 is more or less the same regarding capacity, and it all will depend on the previous parameters.