RBR20 & RBS20: Additional bands detected

[nettyvam]

Hi all, I'm running at RBR20 & RBS20 mesh setup. While using Netspot to determine the signal strength between the router(RBR20) and satellite unit(RBS20), i found that besides the 2.4G & 5G bands for client-devices to connect, and a 5G band for wireless backhaul, there are additional 2.4G and 5G bands.

Eg if only RBR20 is running (RBS20 is powered down), two 5G bands and one 2.4G bands are avail for client-devices to connect (they are of similar but different mac addresses). Also 2 other (a 2.4G '[Hidden SSID]' and a 5G '[Hidden SSID]' bands showed up too. I know they are from the RBR20 as they disappear once the router is powered down and return whenever the router is up and running again.

I understand the triband router is only supposed to have 3 bands: 1 x 2.4G, 1 x 5G, 1 x 5G for backhaul. I could not find any further info on those additional bands. Can anyone advise what are they for please? I discovered this while trying to find the best location to place the RBS20. I'm using the Netspot app -dBm readings to find the best place, since the RBR20 setting page only indicates 'Good' or 'Weak' status (How good is 'Good'?)

Greatly appreciate the time taken to read this post and any sharing that allows me to understand the bands and what i can to optimise the satellite placement..

* The RBR20 and RBS20 are on firmware: V2.7.4.24 

[plemans]

Using a guest network? 

[CrimpOn]

What you are seeing is normal.

There is a difference between frequency bands (channels) and WiFi SSIDs.

Most Orbi routers broadcast Beacon Frames*** on three channels (there are some "dual channel models"):

• 2.4G channel for user devices and potential router to satellite connection****.
• 5G channel for user devices
• 5G channel for router to satellite connections

On these channels, the router broadcasts Beacon Frames for a variable number of SSIDs.

• Primary WiFi SSID will be broadcast on the 2.4G and user 5G frequencies.
• If the Guest WiFi option is enabled, the Guest SSID will be broadcast on the 2.4G and user 5G channels.
• If the router has enabled an IoT network (which the RBR20 does not support), that SSID will be broadcast on the channels that have been enabled (IoT allows using 2.4G only, 5G only, both, or neither)
• The "hidden" SSID broadcasts Beacon Frames on 2.4G frequency and the 5G router to satellite frequency.  Scanning programs such as NetSpot and WiFi Info View (free for Windows from Nirsoft) detect and report on WiFi networks with both visible and "hidden" SSIDs.

*** Beacon Frames are a part of the management mechanism for WiFi:

https://en.wikipedia.org/wiki/Beacon_frame 

**** If the router and satellite cannot make a strong connection on the 5G frequency, they attempt to connect on the 2.4G frequency.  This hidden network is always "there" in case it is needed.

[nettyvam]

No.. the guest network has been disabled as there is currently no use for it. This is a new setup and the only client devices connected to it are just a phone (for me to walk around to check on the signal strength) and a laptop. There are no IOT devices or anything else connected to the network.

[nettyvam]

Thank you so much for the detail sharing. Didn't know about the beacon frame until now!!

Apart from the 2.4G and 5G 'hidden' channels, there are 2 other visible 5G channels (They are different channels on the 5G band, correct?). I have noticed my devices connecting (it shows on Netspot which mac address is the phone, ie the client-device connected to) to either one of them and it seems to be random. 

If one of the 5G channels is for broadcasting beacon frame, will a client-device still be able to connect to it? (I would think we can put aside the 2.4G band for now, assuming it works exactly the same way, apart from it being on the 2.4G band.)

Or will the router perhaps randomly assign one if it's mac address for 5G beacon frame broadcasting and it's other mac address for 5G client-device connection, meaning the 2 mac addresses may be assign the opposite role the next time the router is power up again. Note that both appear with the same SSID.They are not 'hidden'.

Ive been trying to nail which is doing what so that i can take a proper dBm reading for both router-satellite and node-client-device to best position the satellite and this has been kinda frustrating.

[CrimpOn]

I think what you will find is that there is only one 5G channel that user devices can associate with.

You have discovered a fascinating feature of the Orbi system. There is one hardware MAC address, and the router creates  variations of it for each of the WiFi connections (2.4G, 5G, user and "hidden")  I deliberately set the test RBR750 to use channels 2 and 40 because WiFi Info View showed that no other nearby WiFi systems are set to those channels:

Notice that all of these WiFi channels have a variation on -CD-D6-02-3E for their MAC adddress.

User facing channels have the SSID ORBI63 and the two 'backhaul' channels have their SSID "hidden"