Seamless roaming

Qinn

10ge

Wow, that are speeds!!

@johnpoz said in Seamless roaming:
... Figured out how to add a 2.5gig usb nic to my nas, w.

2.5gig usb nic? you mean a 2,4 GHZ usb nic

Edit1: USB nic well can be very handy, I must say I favour wireless bridges, with antennas and no more hassle with drivers.

johnpoz

No I mean a 2.5gbps ethernet nic via usb..

Multigig - 802.3bz allows for speeds of 2.5gbps and 5gbps
https://en.wikipedia.org/wiki/2.5GBASE-T_and_5GBASE-T

Here is the usb nic
https://www.club-3d.com/en/detail/2467/usb_3.2_gen1_type_a_to_rj45_2.5gbps_adapter/

The only thing I dislike about my synology ds918+ nas is that no 10ge support.. Can not add card.. some of their other models do support adding 10ge cards. (hindsight is always 20/20 after you purchase) But someone figured out how to do the driver for these usb sorts of nics.. Its a bit of hassle since it haven't figured out how to auto bring up the nic on a reboot.. So you have to do a bit of manual enable on a reboot of the nas. But that really only happens on a OS update..

So originally - hey use of smb3 multichannel will get me 220ish MBps - that is all I will need ;) And that worked great.. Manual manipulation of the smb.conf.. Since its not really officially supported, hoping the dsm 7 when it comes out adds this to the gui, etc..

And was very happy with that - then ran across people playing with these 802.3bz usb nics.. And other guy got a 5gbps nic working.. But at 80$ each (my pc would need ability to do 2.5 gig as well - since no 10ge card or room to put one) and didn't really think my drive speeds could really fill up 5gbps pipe anyway.. Then someone posted that they got this cheaper $40 each nic to work with 2.5.. That could be a bit of a boost, and under the 100$ what did you buy now look from the wife ;) Figured hey locked down anyway (covid) little side project to play with.

At first thought hey could do smb3 multichannel with the 2x1 nics and the 2.5 nic for a total of 4.5 - but smb3 multichannel doesn't play that game :( if the interfaces are different speeds - it uses only the fastest one vs multiples..

So ended up going from 220ish MBps transfers to and from nas and my pc.. To 280ish - 50-60MBps bump.. Nothing to sneeze at for under $100 and a few minutes of play time setting it up.

Qinn

@johnpoz said in Seamless roaming:

2.5gbps

Through XPEnology ...? https://xpenology.com/forum/topic/17690-drivers-for-usb-30-to-ethernet-255-gbit/

johnpoz

No official DSM from synology.. Just using the r8152.ko driver.

Here is the reddit thread
https://www.reddit.com/r/synology/comments/fkb3gm/proof_of_concept_25_gbps_usb_ethernet_adapter/

And I am running 6.2.3 and work just fine.

Qinn

@johnpoz <off-topic> I see the bullet (online status) with your avatar is green, mine is always greyed out, is that a settings thing or is it something my DNS/IP blocker blocks? </off-topic>

johnpoz

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

tman222

@JKnott said in Seamless roaming:

@johnpoz

I just looked at the data sheet for that unit. I see they still support 802.11b. I wonder if anyone still uses that. I hope not, as it's a performance killer for the entire area. The local library stopped supporting it several years ago and I have my AP configured for N only, as every device I have is capable of N. It's a performance killer because every device that wants to use g or n has to go into b compatibility mode, where it sends a b frame to reserve time for the g or n frame. G only doesn't cause such a significant performance hit for n, as the n device just has to slow down the header, when there are g devices in the area.

There are a couple options to get around this, both supported by Ubiquiti Unifi wireless gear:

Enabling Air Time Fairness
Enabling 2G/5G Data Rate Control and disabling CCK rates

JKnott

@tman222

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.

Qinn

@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.

johnpoz

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

JKnott

@johnpoz

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.

johnpoz

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..

JKnott

@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.

tman222

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.

JKnott

@tman222

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.

tman222

@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.

JKnott

@tman222

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.

tman222

@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.

JKnott

@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.

johnpoz

@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?