Question Line topology with T-PLink Deco XE75?

rasmasyean

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Hi,

I just bought a 3 pack Deco mesh router system.

The internet is on the 3rd floor and I'm trying to make a diagonal to the 1st floor.
The Main Deco unit connects to both the 2nd and 1st floor units (thus making the 1st floor unit slow).
I thought it was automatically supposed to connect to the closest unit, but both seem to connect to the main.

Is there a way to make it connect in a line?

Thanks.
 
It really depends on the mesh system. Most function they way you describe, all the remote units hook to the main unit.

Even if this works you are going to get a massive bandwidth penalty. Could be well over 75% slower but it depends on the details of the mesh implementation.

I try to never use mesh systems if there is any other option so I can't say what ones can do what you want.

Do you have coax cables in the room by the router and the remote rooms. You can use MoCA to carry the signals. MoCA unlike wifi can get full gigabit speeds. You can also consider powerline networks to connect between the rooms.
You can use same mesh units you have over these technologies to provide the wifi. They just connect back to the main router via what appears to be a ethernet cable but it is actually one of these other technologies.
 
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rasmasyean

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Really? That's not a "mesh". That's more like a "star". Is this some type of marketing ploy they make you fall for? I had the impression that all the routers are pretty much independent and talk to any other router they are signally closest to at different timepoints. Like if they are equidistant, they would make a triangle of communication, etc.

I don't have coax cables in the rooms.
 
There is no definition of mesh so manufactures would call a rock a mesh device if they though they could get away with it.

Some mesh unit do function as true mesh. But many of those are still extremely flaky because wifi signals change in intensity and you don't want your network constantly re configuring itself. The better units will have dedicated radios for the traffic between the units. These extra radio chips increase the cost of the units though.

Be aware even if it function the way you want you now will have 3 wifi signals between you and the main router that can get interference. There is only a very limited amount of wifi bandwidth and just a single router with no mesh unit is close to using it all. So the unit have to reuse the same radio channels. This of course is ignoring that your neighbor also is likely trying to use all the radio channels and stomping on your signals.

You should really try not to use any kind of mesh system if you have any other options.
 
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rasmasyean

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OK, regarding the original question, it's now "line topology" after like half a day. I guess it took a long time to figure out how to reconfigure itself.

This unit has a 6GHz backhaul which can be shared with clients, but I'm not going to open that share setting up yet because I don't think anyone here has anything that connects to that band.

I mean, not that I know much about WiFi specs, but if I were to design this thing, I would make the routers not overlap channels with in-range siblings. Neighbors...you can't control of course. But what happens when someone walks from one end of the house to the other? Does it have to keep the channel going to prevent a "re-connect sequence" or whatever? A cell phone would change channels automatically because the tower tells it to, right? That's why you can talk uninterrupted, right?
 
It will "mostly" figure it out. BUT it is the end device and not the network that does the roaming. The end devices are not real smart sometime and will stay connected to a weaker signal even when a better one is available. Mostly this is because the unit is using the radio for communication and if it scans for better radios it will cause outages. Its a trade off because if it looks for a new signal too much it will just constantly jump around.

This is where home user think you just stuff magic boxes in your house and you get magic wifi coverage. It actually takes very careful planning and placement. You need to have as little overlap as possible between radios both to prevent interference when they are using the same channels as well as to help the end device properly select the correct location. Too much wifi is many times as bad as not enough. There are people whose whole carrer is design of wifi networks for corporate installs. Note large companies do not use silly mesh systems they use all ethernet connected AP.

In general as long as you are not the stupid person who watches netflix while he falls down the stairs in his house it will switch over "ok". You always get a small re connection drop but it is tiny and you will never see it in most cases, you would not even get disconnect from say a online game.
The larger problem tends to be it does not switch when you have too much overlap between your radios. You can just stop and start the wifi client and in most cases it will connect to the "best?" signal.

Wifi was never designed for mobile users. Unlike a cell phone where the network is in full control of the radio chips in the cell phones.
 
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rasmasyean

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I think I'm seeing "static" clients constantly switching between nodes now. Does it like "get used to" all the clients or something and try to give them better signals when one is getting more interference from neighbors? As in, it says to the others, "OK, this client is dropping to 50MBps, but I know you can 100MBps because you've done it before so why don't you take over?". Or perhaps it's just, "OK, I'm getting swamped by the other clients near me, but I know you're within range of this client so you can have him."
 
The network/mesh has no ability to control where the end clients connect. The clients are in full control.

What some do is try terminate a client from the network side to try to force it to change. That is a very risky thing to do because the client might just connect back to the same radio source. The problem is the network only can tell the signal levels coming from the device it can not tell how strong the signals are that the device receives.

The only way to really do this is for a new wifi standard to be developed where the network controls the client radio. Many years ago cisco had a system that would allow roaming even outside the building to say a cell network. It required you load software on the device and it only worked with a small number of devices. It was a huge pain and the level of access required to make this work would never be allowed by android or apple on modern cell phones
 
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rasmasyean

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I'm not sure I follow. Why do you need the client radio to change? All you really have to do is broadcast signals that address the client from a different source (i.e. router2 vs. router1). The client can't really tell which direction the signal is coming from. For all the client knows, the router just teleported closer to it.
 
If it were that simple :)

Traffic is not really broadcast out all the wifi nodes on a network it is only send out on the AP that actually has a connection to the end device. Partially this is because the traffic is encrypted. The encryption method used has the mac address of the end device and the mac address of the AP as part of the session keys. This is to prevent spoofing even when you know the preshared key. If you run on enterprise mode with a radius server it is even more complex because then the AP must transfer this authentication between the AP to avoid having to run another authentication cycle with the radius server.

The connection concept of wifi is why even without encryption you get very small outages as you are negotiating a session with the new wifi AP.

A cell network does this and much more since you can actually move to another providers network. Because it can in effect talk to the radio chip in the background to the data communication and tell it when and where to connect it can much more efficiently do roaming. You still hear the handoff even on cell phones sometimes.

If your problem is the client roam to much most wifi nics have a setting that controls this. There is no fixed name but a common one is roaming aggressiveness.
 
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