Mesh vs. AP - roaming protocols?

[helloguys]

I know that this topic has been discussed many times. But I was not able to find the discussion specific to roaming protocols (i.e. 802.11k, 802.11r and 802.11v).

Let say, if wired backhaul is not a problem, it is said that AP would be a better option than mesh. Just configured APs with same SSID and password and it should just work.

But I thought one of the advantage of "Wi-Fi System" is to support roaming protocol (of course client will need to support it as well). Do we know which mesh system actually supports those protocols? Also, in real life, does those protocols make any noticeable difference?

Currently, my main router is Netgear X8 (R8500). My satellite AP is Netgear R6300v2 with wired backhaul to the main router. I configured both with same SSID and password. When I walk around the house, I can tell the Wi-Fi client roaming by looking at the BSSID (MAC address of the AP). Obviously, above mentioned roaming protocols do not exist in this setup. But I didn't feel any "gap". Anyone has different experience? Thank you!

Reference:
https://support.apple.com/en-us/HT202628

 

[thiggins]

The Wi-Fi Finder shows 11kvr support for many mesh systems.

As for whether it makes a difference:
https://www.smallnetbuilder.com/wireless/wireless-features/33195-wi-fi-roaming-secrets-revealed

 

[Trip]

In addition to what Tim has offered, here's a Cisco fast transition roaming guide that accompanies their Mobility Express platform, delving into .11k/v/r at a more in-depth, yet still mostly understandable level. It's also a good illustration of the difference between what enterprise wifi systems are capable of offering in this area versus SOHO products.

The initial thing to keep in mind is just because you might have a wireless mesh does not mean you automatically have 802.11k/v/r fast-transition roaming (FTR) present (a mesh being nothing more than an intelligent interconnect of multiple APs that share topology awareness -- give or take). There are plenty of "mesh" products (most of them in the consumer and SMB space) where FTR is either not implemented, only partially implemented and/or supposedly implemented yet non-compliant and/or bug-ridden. It's not until you look at the higher-end of the market, typically in the enterprise products, where you see "mesh" typically inclusive of full and properly-implemented fast-transition roaming.

That said, and as much of the SNB article eludes to, the proposed benefits can't always be realized, and thus aren't always necessary, as is often the case with very small networks, ones with certain types and/or numbers of excessively "dumb" clients, etc. In your case, your broadcast topology, APs, wifi client and workload fall into place well-enough without FTR that the addition of it may not have yielded any noticeably better behavior, if any at all. Juxtapose that against, say, dozens of concurrent wifi VoIP calls to/from quality mobile SIP handsets (that are proven 802.11k/v/r-capable and standards-compliant), attached to workers on foot in a factory or office building, and FTR being present on that wifi platform could very much make a difference. It all depends on the context surrounding the wireless environment and outcome goals.

 

[thiggins]

The other thing you need to watch with mesh products is that you may end up with more nodes than you need. Most STAs make roaming decisions based on RSSI levels. If there is too much overlap between APs/mesh nodes, signal levels may never get low enough to trigger a roam. Or the device may ping-pong back and forth between APs.

Keep in mind that, in my experience, 11k and v don't provide sub-second roams, if that's what y0u're looking for. Only 11r has the potential to provide that and it's not widely (and/or properly) implemented in consumer gear.

 

[Trip]

The other thing you need to watch with mesh products is that you may end up with more nodes than you need. Most STAs make roaming decisions based on RSSI levels. If there is too much overlap between APs/mesh nodes, signal levels may never get low enough to trigger a roam. Or the device may ping-pong back and forth between APs.

An excellent point to keep in mind, indeed. Even with a site survey or two, I've had to adjust AP power levels, even relocate a few APs, to accommodate for exactly that behavior.

Keep in mind that, in my experience, 11k and v don't provide sub-second roams, if that's what y0u're looking for. Only 11r has the potential to provide that and it's not widely (and/or properly) implemented in consumer gear.

That's what I've noticed as well regarding most SOHO products, which is why when proper .11k/v/r is required/desired for residential or non-production, I'd rather go with working-pull and/or refurb enterprise gear with way more proven software stacks, if/when I can get away with it.

 

[sfx2000]

Keep in mind that, in my experience, 11k and v don't provide sub-second roams, if that's what y0u're looking for. Only 11r has the potential to provide that and it's not widely (and/or properly) implemented in consumer gear.

11R's main benefit is for WPA/WPA2 Enterprise, where there's a Radius Server involved, and having to pass the keys on the back end from AP to AP...