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I am really excited to write about WiFi6 (802.11ax), which is the next generation WiFi  after 802.11n (WiFi4) in 2009 and 802.11ac (WiFi5) improvements in 2013/2016.

Note that WiFi6 is WiFi Alliance certification (to be published Q3-2019) based on upcoming IEEE 802.11ax amendment (to be ratified Q3-2020). Here is a brief comparison between WiFi5 vs WiFi6.


Cisco recently released 3 different models in 9100 series that supports 802.11ax. (They also released MR45 & MR55 models in Meraki as well). Here are the links to datasheet for 9100 series models.

  1. Cisco 9115
  2. Cisco 9117
  3. Cisco 9120

Cisco started naming these APs as Catalyst APs Oppose to Aironet APs (C9117AXI-B vs AIR-AP4802I-B) based on their flagship product “Catalyst”. Here is a great video talk about differences between these models.


Primary objective of WiFi6 to improve performance of WLAN in high density environments. This is a really great article from National Instruments that explaining enhancement introduced in 802.11ax in details.
Introduction to 802.11ax High-Efficiency Wireless

  1. Orthogonal Frequency Division Multiple Access (OFDMA)
  2. Target Wake Time (TWT)
  3. MU-MIMO (both uplink & downlink)
  4. BSS Coloring (Spatial Reuse)
  5. 1024 QAM Support
  6. Up to 8 Spatial Stream (SS)

There were really great CLUS presentations that talks about different aspects of WiFi6. You should go through them to understand what’s coming with Cisco 802.11ax APs. Here are the links for those presentations (if you do not have account, you can create one free of charge).

  1. BRKEWN-3010 : Understanding Cisco RF Features by Jim Florwick
  2. BRKEWN-2017 : Understanding RF & Radio Design of WiFi6 by Fred Niehaus
  3. BRKEWN-2010 : Introduction to Next Generation Wireless stack by Sujit Ghosh
  4. BRKRST-2515 : QoS Design and Deployment for Wireless LANs  by Rob Barton
  5. BRKEWN-2006 : Advancements in Wireless Security by Sthephen Orr

During my recent visit to Cisco HQ, they gave me C9115AX & C9117AX model for testing. (Note that Cisco invited me JustTheTech-802.11ax introduction event that I could not attend in person, so I got those APs later on).


In my testing I have registered AX9117 AP in local mode to 8540 running on AireOS Cisco AX9115 in sniffer mode capturing WiFi6 traffic on a WLAN configured with WPAv2-PSK with FT. Used LiveAction Omnipeek to receiver of those captured packets.


Here is a beacon frame that you can see HE (High Efficiency) capabilities in it. Note that these Cisco AP based on IEEE802.11ax (Draft 3.0). Here is the pcap file if you need to go through it.


Having few number of clients on the 9117AP, I got reasonably higher speeds on Samsung S10 clients (530 Mbps upload vs 685 Mbps download). Since 802.11ax talks about higher efficiency, more testing to be done to see how performance impact when we add more clients to the cell.



Here is the raw packet capture taken during these clients connecting to the SSID & of beacon frames/Probe Request/Probe Response for your references.

Here is the “debug client a8:db:03:8a:of:9e” (one of 802.11ax client) output on WLC while one of those ax client trying to connect.

As I play with these AP, will do more posts in future.

Related Post

  1. Cisco Catalyst 9100 Series: 802.11ax APs to be excited about by @baldwifiguy
  2. Clear to Send (CTS) Podcast- 802.11ax 
  3. MCS table updated with 802.11ax rates by Francois Verges
  4. WiFi6 Deployment Guidelines & Scenarios by Wireless Broadband Alliance