if openwrt is presented with two or more individual wireless devices, for example on an board wifi card and an external usb wireless dongle, but only had a single ssid set up, how does it manage these resources?
For example, will it automatically balance the load accross the two devices, or does it ignore the weaker device and automatically accept things that try to connect to the one with the strongest signal?
If a connected device supports it can both nic be combine or multiexed together for faster or more stable and data transmission to a single client.
Us there a user option choose.
I'm not asking if this is a good idea, only what openwrt does/can do in this situation.
a link aggregated connection doesn't provide higher speed, only higher bandwidth.
two parallel transfers will still max out at 1gbit (if you use gigabit ports), but you can have them both running at full speed.
Without elaborate RF filtering (such as the two 5 GHz radios in a "tri band" router have), operating two radios in the same box on the same band (even different channels) will jam each other and there will be very poor performance.
When presented with multiple APs with the same SSID, the client decides which one it will connect to. Clients only having one radio can only connect to one AP at a time.
I guess that a better question might be what is openwrt capable of doing, and what are its limitations, if it has more than one wireless nic.
my draytek have multiple antenna all that can function independently, and can dedicate one antenna to one device, and another to another device on the same ssid. or it can use a pair to connect to suitably capable devices at "double" the bandwidth. at least according to the marketing. I've never actually confirmed the claim as my use is so light that I'd need to benchmark it to tell.
Presumably it does something to avoid conflicts. I will need to check the manual to find out what it calls this.
Without venturing into the technicalities, here is a simple "Executive Summary" (Anyone who has worked in development in an IT department of a large Corporation will know what I mean)
Most modern wireless routers have at least two wireless devices, one on 2.4GHz and one on 5GHz, with both running simultaneously.
The "ssid" is purely for the benefit of us humans and is usually a readable string of characters, like "MyHomeWiFi" or whatever you want. It does not have to be unique.
"Under the hood" is the Basic Service Set Identifier (BSSID). This must be unique and is actually the mac address of the wireless interface.
OpenWrt is a router operating system, so you might expect it can do all sorts of fancy things.
It can.
Not only are multiple "wifi cards" and "wifi dongles" supported simultaneously, each actual piece of hardware supports "Virtual wifi cards", aka Virtual InterFaces (VIFs).
Each hardware "wifi card/dongle" will present itself, via its drivers as one or more Wireless Physical device (WIPHY), with each one of these supporting numerous VIFs.
So you can see OpenWrt is very powerful, managing all the potential WIPHYs and VIFs
As a general rule, no, although new standards, like Wi-Fi 7 (802.11be) can potentially support this, but it is early days with most user devices, like smart-phones etc. not yet supporting it.
Just as an explicit addon note.
These multiple virtual wifi interfaces, can be like 1 802.11s interface and/or up to 4 access point network interfaces.
@bluewavenet had for sure more hardware in his hands then me, and could probably add some annectodes what you could find out there.
These functions depend on the hardware, it's firmware and the Linux driver which OpenWrt is using.
@PB-97 A quick dip into the ocean of technicalities, you can run the command iw phy then look for "valid interface combinations".
For example a GL-MT6000 has a MT798x series wireless chipset and it gives the following for each of the two wiphys on the chip:
valid interface combinations:
* #{ IBSS } <= 1, #{ AP, mesh point } <= 16, #{ managed } <= 19,
total <= 19, #channels <= 1, STA/AP BI must match, radar detect widths: { 20 MHz (no HT), 20 MHz, 40 MHz, 80 MHz, 160 MHz }
In this case, each WIPHY supports any combination of AP and mesh up to a total of 16 VIFs.
So, for example, 15 access points and 1 mesh (times 2 for both WIPHYs). Probably unlikely to be used, but it just goes to show what is possible.
Didn't Asus start putting this on laptops well over a decade ago,and I seem to remember that the net gear nighthawk gaming routers have been doing this for a while now, at least that's what the marketing material described it as.
whether or not it is exactly what we're talking about is another matter.
Even if they did (they didn't), there were no (zero) client devices (before wifi 7/ 802.11be, and as mentioned, even for those it's still very early days for MLO) which could have made use of that.
They might have done something proprietary/non-opensource, but I have not heard of it. You may be thinking of something else the marketing guys have been saying to get sales.
It is only recently with 802.11be (aka wifi7), that anything has been defined in official standards.
This is known as Multi Link Operation (MLO) and MUST generally be done all in the hardware (on chip).
Lets say you have two devices supporting MLO and you want to stream data packets from one to the other.
The chipsets in each device will have to negotiate with each other, then the sending device will split up the packets of the stream, sending some on, say, 5GHz and some on 6GHz.
The receiving device must then reassemble the stream with the packets in the correct order - not a trivial process as you can imagine, and the reason it is (will be) done at the chip level.
