Wireless Standards for Catalyst 9800 WLC and Catalyst 9100 AP

[okm]

Hi,

I checked data sheets of Cisco Catalyst 9800 Wireless Controller (Cisco Catalyst 9800 Series Wireless LAN Controllers - Cisco) and Cisco Catalyst 9100 Access Points (Cisco Catalyst 9100 Wireless Access Points - Cisco - Cisco).

Cisco Catalyst 9800 Wireless Controller supports the following wireless standards:

IEEE 802.11a, 802.11b, 802.11g, 802.11d, WMM/802.11e, 802.11h, 802.11n, 802.11k, 802.11r, 802.11u, 802.11w, 802.11ac Wave1 and Wave2, 802.11ax.

Cisco Catalyst 9100 Access Points. supports the following wireless standards:

IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ax, 802.11h, 802.11d

Does it mean that if I connect 9100 APs to 9800 WLC, some of the 802.11 features are not supported?

For example, I see that WMM/802.11e, 802.11k, 802.11r, 802.11u, 802.11w are only supported in 9800 (not supported in 9100). So, a network with 9800 WLC and 9100 APs can't have 802.11e/k/r/u/w supported?

Thanks!

[Leo Laohoo]

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@okm wrote:
For example, I see that WMM/802.11e, 802.11k, 802.11r, 802.11u, 802.11w are only supported in 9800 (not supported in 9100). So, a network with 9800 WLC and 9100 APs can't have 802.11e/k/r/u/w supported?

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All of the features are software-driven. 

The 9800 is a WLC and not an AP.  The AP might/can have these features enabled if WLAN business unit allows.  

[okm]

Hi Leo Laohoo,

Thanks for your reply. Yes, I am aware that 9800 is WLC and 9100 is AP. My question was if I buy one 9800 WLC and two 9100 APs, and build a small network (two 9100 APs connected to one 9800 WLC), can this small network support all the 802.11 features of WLC mentioned above? I am asking this because according to the data sheet, 9100 AP does not support some IEEE features 9800 WLC supports (such as WMM/802.11e, 802.11k, 802.11r, 802.11u, 802.11w).

Thanks!

[Leo Laohoo]

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@okm wrote:
I am asking this because according to the data sheet, 9100 AP does not support some IEEE features 9800 WLC supports (such as WMM/802.11e, 802.11k, 802.11r, 802.11u, 802.11w).

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Information found in the Data Sheet can be misleading, if not, vague.

9100 is a large family of APs, from 9110 to 9166.  And the Catalyst 9k APs are divided into two "distinct" groups.  9110 until 9120 have a wireless chipset made by Broadcom.  9130 up to 916x have a wireless chipset supplied by Qualcomm.  Coding for both, particularly chipset supplied by Broadcom, is not easy.

Another thing to consider is this:  Not all features under 802.11 will be "relevant".  Many standards have a "all in" approach.  For instance we do not enable 802.11k, v or r because legacy wireless clients do not support them and will have issues joining an SSID with these features enabled.  

802.11ac, 802.11ax might be the new standard presently but, at the end of the day, 802.11n is all anyone needs.  

[Leo Laohoo]

• 802.11k and 802.11r have been supported since AireOS and this feature has been ported to IOS-XE.
• 802.11u is Hotspot 2.0.  This has been supported since AireOS and this feature is found in IOS-XE.
• 802.11w is MFP.  That has been an AireOS standard since time eternal and this feature is in IOS-XE.
• WMM is a subset of 802.11e.  If the wireless network does not support 802.11e, then WMM will not work.  And whoever codes a firmware that does not support 802.11e is going to get laughed at by the industry.  

These above standards are found in AirOS and IOS-XE.  They are supported by all Cisco APs from 3500, 2600/3600, 2700/3700, 2800/3800/4800/1560 and up to Catalyst 9k APs.  

The most critical aspect (or question) are the wireless clients.  If wireless client, for instance, do not support 802.11w, but the SSID has MFP set to "required" or "optional" then there is a strong chance said wireless client is not going to join the SSID.  

I cannot speak for anybody else who's been in the WiFi business long, but I have seen my fair share of "IoT" (Internet of Trash).  I have seen WiFi clients who are marketed as 802.11a/n-capable but requires 802.11b (with 1 Mbps Data Rate) before it could join the SSID.  And just recently, last Friday, an MFP-capable wireless client which has MFP set to "optional" cannot join an SSID with MFP set to "optional".  The wireless client will only join the SSID when MFP was disabled (on the SSID).  

What am I trying to say?  These nice-to-have "standards" are of no use if the dumbest wireless clients refuses to honour either one of them.  And there is a rule-of-thumb in the wireless industry and it is, "Always design the wireless network based on the least-common-denominator" (aka, the dumbest wireless client).

[Rich R]

The Cisco documentation leaves something to be desired - datasheets and config guides are incomplete.
Refer to https://www.cisco.com/c/en/us/td/docs/wireless/access_point/feature-matrix/ap-feature-matrix.html for some more info on feature support on various APs - again this doesn't cover every possible feature and standard.
The only way to be sure is to test and verify yourself.  You could also ask your Cisco account team but the answers will depend on software version used and AP model and they may need to check some details with the wireless business unit.

[docjb0221]

Hello,

Some of the standards you mentioned are not radio standards as such but are wireless client standards. These standards, like 802.11k, require specific radios to work. The 9800 configuration guide mentions Assisted Roaming (802.11k) as one such example (https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-9/config-guide/b_wl_17_9_cg/m_assisted_roam_9800.html). It requires radios capable of 802.11n.

[Gaurav Kansal]

Dear okm,

All mentioned standards are supported by earlier access points other then 9100 series and 9800 controller still supports those earlier access points models.