Seamless roaming
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Do those do anything about not requiring the the b protection frames? That's the killer, where before a g or n frame is sent, a b frame has to be sent to reserve the time that b otherwise wouldn't know about.
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@johnpoz said in Seamless roaming:
No you just set that in your profile
Maybe yours is set to invisible... I don't know what it shows when not logged in.. Maybe it always shows me online, even when I am not.. Which really rare to be honest - I spend WAY TOO MUCH time here ;) hehehehe
Aha, it has to be set manually everytime.
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you can just disable B.. Pretty sure its default to off In your wifi group
Legacy Support
Enable legacy device support (i.e. 11b)You would have to check that for B
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That wasn't my question. Of course you can disable b on an AP. What my question was about is the b protection. That is what happens when an AP, configured for g or n hears a b frame? My understanding is that it still has to protect b when it hears b, whereas when n hears g it only has to transmit the headers at g rate, but the rest of the frame goes at n rate. This does not cause anywhere near as much of a performance hit, as b protection does. This is all part of the avoidance part of CSMA/CA, ensuring all devices do not transmit, when another is transmitting.
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And how exactly would it hear this B frame? If this B device wasn't actually connected to the network..
Your saying that some B device not associated to your wireless network..
Your saying that a neighbor running some B network at his house say on channel 1, slows down my 2.4 N network running on say channel 6.. Because my AP can somehow hear these B frames? Yeah that makes ZERO sense..
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@johnpoz said in Seamless roaming:
And how exactly would it hear this B frame? If this B device wasn't actually connected to the network..
Ummm... we were talking about WiFi. The CSMA/CA is intended to prevent multiple WiFi devices from interfering with each other. Part of this collision avoidance is achieved by listening to the headers, to determine how long the channel will be occupied. While g & n use the same modulation method, b doesn't, which means b cannot understand g or n headers. To get around that, after hearing any b signal, the g or n device must transmit a b frame to tell the b devices how long the channel will be occupied, so that it won't try to transmit in that time. So, for example, I have an n only network. If my neighbour was running g, then my devices would hear the g frames and then transmit only the headers at g rate then the rest of the frames at n. If that neighbour was running b, then my devices would first have to transmit a b frame, with the sole purpose of telling the b devices how long the channel will be occupied. It does not require the devices be on the same SSID, only be physically close enough to interfere. This is covered in the O'Reilly book 802.11 Wireless Networks The Definitive Guide, by Matthew Gast.
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Here is another article that also explains this:
https://www.excentis.com/blog/disabling-80211b-support-your-ap-or-not
I think disabling CCK rates (DSSS) is one way around this, though at the expense of AP coverage distance. However, if a wireless network is well designed with proper cell sizes, I don't think it would be a big deal. I will say that after explicitly disabling CCK rates I did see noticeable drop in channel utilization on the 2.4GHz band.
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Here's what Wikipedia says about CCK. It just affects the modulation of the b signal. However, a b frame is still transmitted and when a g or n device hears it, the b protection kicks in.
That article you linked to describes the problem:
802.11b client on your/neighbouring network
New Wi-Fi specifications have always been designed with backwards compatibility in mind. In case of backwards compatibility for 802.11b clients, this results in adding one or two (decision is up to the vendor) extra messages (sent at 802.11b speeds) before each data exchange between an 802.11g/n/ac AP and 802.11g/n/ac clients. Using this RTS (Request-To-Send) and CTS (Clear-To-Send) messages, as they are called, the 802.11b devices are informed of the upcoming OFDM-modulated data exchange which they will be unable to decode. And, as always in Wi-Fi, the golden rule says: once you are informed, you can not interfere.
This seriously impacts the total efficiency of your network, as each data exchange is piggy-backed with these slow RTS/CTS messages. An AP will automatically enable this protection mechanism as soon as an 802.11b client is detected on the same channel (not necessarily on the same SSID) and will inform all other clients on the network to enable this protection. So performance impact happens, even when 802.11b clients are not sending anything.
So, hopefully, no one is still using b, but even having it enabled on an AP will kill performance. Generally, you shouldn't allow anything slower than your slowest device. Since all my devices support n, I don't even allow g on my network. Despite that, if my neighbour uses b, I get the performance hit regardless.
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@JKnott - if CCK rates are disabled and the AP sends out beacons using ODFM, wouldn't that prevent 802.11b from being seen / trying to associate since they do not understand ODFM? Or am I misunderstanding this? Thanks in advance.
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If you want to disable 802.11b, then why not just disable it? It's an option on every AP I've worked with, other than the ones that were b only. If all you're doing is changing the CCK rates, you're only affecting possible bandwidth, not disabling b. Also, as far as I'm concerned, b should be off by default, as many people don't bother worrying about such things. Only turn it on if you have an absolute need for it. Of course, and device that supports b only would have to be ancient.
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@JKnott - Yes that makes sense and 802.11b is off by default in Ubiquiti Unifi wireless gear. However, if an AP has 802.11b disabled already and you also choose to disable CCK rates and increase data rate control on the 2G band to 12Mbps, does b protection still take place? Or would the AP then just ignore any b frames altogether? Thanks again.
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@tman222 said in Seamless roaming:
Or would the AP then just ignore any b frames altogether?
My understanding is b protection is always on. You can't turn it off. This is why it's important to not even enable it, unless you need it to support some ancient gear. I'm glad that b is off on that AP. I have a TP-Link AP and, with it, when I turn off b, I also lose g. Then again, TP-Link is not known for brilliant designs. This AP has the same VLAN problem as some TP-Link switches.
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@JKnott said in Seamless roaming:
Then again, TP-Link is not known for brilliant designs.
QFT ;) hehehehehe
As to B devices slowing down your 2.4 - yes this is why you don't run your 2.4 on the same channel as your neighbor ;) Then again.. It's not the end of the world - its not like that b device over on the neighbors running on channel 1, is going to knock your channel 6 2.4 wifi network down to b speeds..
To be honest - really the only things that use 2.4 really don't need 400mbps anyway ;) My thermostat works just fine even it was at B speeds, same goes for my light bulbs, etc. Anything that needs decent wifi speeds should be on AC on 5ghz.. So what that neihbors B devices do means nothing in the big picture.. "EVEN" if it was slowing down my thermostats wifi speed ;)
On a side note - who would be running any sort of b devices in this day an age anyway?
My 3 ap see a total of 135 near by AP... Not 1 is listed as being b ;) Scans for interference levels are in the dirt -95 dbm sort of levels.
Also lets remember that B pretty much died off when G came out back in 2003.. Really how and the F would still have any sort of B devices running? In 2020?
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@johnpoz said in Seamless roaming:
To be honest - really the only things that use 2.4 really don't need 400mbps anyway
My ThinkPad E520 only does 2.4 GHz, so it needs it. My phone and tablet can do 5 GHz though. Also, I live in a condo and at least a dozen other SSIDs turn up, so no matter which of the 3 clear channels I pick, odds are someone else is using it. The best thing people can do is make sure b is not enabled and the problem goes away.
PfSense running on Qotom mini PC
i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
UniFi AC-Lite access pointI haven't lost my mind. It's around here...somewhere...
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Get a couple Ruckus R600s off eBay that run "unleashed" (basic controller on the APs) and have a cocktail while you roam to your heart's content. They can be found for somewhere around $100 each these days it looks like.
I know I disabled dot11b. I think I had to ssh into the APs to do it. It was easy.
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@JKnott said in Seamless roaming:
The best thing people can do is make sure b is not enabled and the problem goes away.
Sure - but it really pretty much is default off these days. My colleague had an issue where her scale that auto uploaded weight stopped working.. It was a B.. you know why it stopped working.. .This was a few years back btw, because comcast disabled b on their router she used..
To be honest bringing it up only confuses users that its something they have to look for and use, or their wifi speeds are going to suck ;) Which its not..
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@johnpoz said in Seamless roaming:
No I just run the controller in a ubuntu vm on my nas... You can manage the AP with just their phone app.. But you loose out on lots of the bells and whistles - and most important information easy to read in a simple to call up webgui..
It doesn't really need much horsepower, and can really run on almost anything. windows, macos, linux. they have people running it on a pi, etc.
Best you someone has put out a docker version of it as well ;) let me check ;)
Yup: docker https://hub.docker.com/r/linuxserver/unifi-controller
Also keep in mind that you can turn on the controller, do whatever you settings you want to do - and then just turn it off.. The AP continue to do whatever.. You just will not get all the history sort of info about your clients and the AP, etc.
Had a look into it, but my Synology doesn't support docker
So the only way to go (when the nanahd will suffice) will be a cloud key or would you advise a something else? -
Not using docker for my controller... What synology do you have.. Specific model? I have a ds918+
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@johnpoz only a meager DS215+
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@Qinn said in Seamless roaming:
DS215+
Ah that sucks.. DS218+ is support for virtual machines..
You have anything else that is on all the time or you could leave on.. A pi perhaps?
You could always use the excuse to update your nas.. If you need to get something past the budget committee (significant other/wife/etc ) heheh
