Access points and SSIDs!

alex_boothby

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Hi Guys and Gals,

Happy New year to all.

I just have a quick question.

At my work we have two Access Points (one upstairs one downstairs) the both operate on different channels but broadcast the same SSID and password.

My question is, how does my laptop know which one to connect to? When I search for wireless networks it only sees one Connection (as in it does not list the SSID twice).

When you clone a SSID is the computer just clever enough to realise it is the same network?

Final question! Would I be able to add another access point (as long as it operates on different channels to avoid interference).
 
yo,

Not sure if all access points are the same, but we use Motorola ones and essentially it is set up as follows:

Router -> Motorola RFS4000 PoE Switch (The wireless SSID is configured on this switch) -> Access Points plugged into switch via structured network

so in short our access points just connect to the switch, and the SSIDs and such are configured on the switch
 
When on the same band and both have the same name, it will only show up as one AP. Change the name of one of them by adding a letter or number at the end. That way you see them separately.

We had that same problem with dual band AP and routers. You have to give each one on each band individual names with some sort of band identifier.
 
I'm going to answer this piece by piece.

My question is, how does my laptop know which one to connect to?

Assuming everything matches like you said it does, it simply connects to the stronger of the two signals. Depending on the AP and/or the wireless device itself, it might not ever switch to the other AP even if it becomes the stronger signal as in my experience most devices are not configured to do this by default. To use an example of this, you arrive to your office and your cell phone immediately connects to the AP on the first floor with full strength. You go to the second floor where the AP on that floor now has full bars but the one on the first is only showing 1 bar of strength. By default you phone will not switch over and connect to the new AP.

When you clone a SSID is the computer just clever enough to realise it is the same network?
It really depends. If the different Access Points are on different subnets then you can't guarantee similar access to resources. However, if they're on the same subnet and they are acting just as access points (not routers) then yes it'll all look and act like it's the same network.

Final question! Would I be able to add another access point (as long as it operates on different channels to avoid interference).

Yup! you can pretty much add as many as you want. As you mention the more you add the more interference you need to worry about. Ignoring interferance and building/environment the only real limit you have on how many APs you can have with the same SSID on your network is the number of available IP addresses on your network that can be assigned to each AP. Keep in mind though that the more APs you have, the less IP addresses are available for your DHCP server to dole out to clients.

Hope that helps.
 
Thank you to everyone for your help. Much appreciated.

Long story, but the reason I am looking into this as my boss struggles to use the Wifi in his office. Even the PoE access point is just out his office, I think due to all the fire doors signal goes thorugh a bit of interference (even though he still gets 3/5 bars of signal).

Dont get me started on why he just cant plug in his laptop to the Ethernet port in the office (maybe he likes to pace and surf?!).

To get round this I was just going to install this in his office http://www.amazon.co.uk/TP-LINK-TL-...?ie=UTF8&qid=1451944031&sr=8-1&keywords=av200

I actually played around with my personal one today and got it to work, but the only problem is it created its own wifi ssid (this would just cause him issues having switch). And like you said, even if the signal is stronger it might not necessarily switch over to it.

When I got home I figured out how to login to the TPlink settings page in which I can set it up with the exact same SSID and Password to clone the access point. I will try this tomorrow. If I do get it to work I just hope his computer will auto switch to the access point in his office and not stick with the one he struggles with.

I have no idea why our IT company did not suggest this. There suggestion was to upgrade to 5gHz Meraki system. Which I am sure would work, just cost a lot more!
 
Powerline isn't really a solution I'd propose to a client either. Without seeing wiring diagrams (or knowing the wiring) of the building, you can't guarantee it'd work.

The Powerline adapters must both be on the same circuit in order to work, if not, then they won't. For example, in my house the plugs upstairs (where my computer is) are on a different circuit to the ones downstairs (where my router is), so a Powerline adapter wouldn't work.
 
Thanks for advice.

Luckily in this case I dont have to use the Powerline aspect as I can use the wifi one as a access point - plug it into the wall to give it power and plug it into a active ethernet port. So I am not having to make the electrical circuit live.

One issue I am now having is that I have cloned the SSID and I can see it works. However, say if you connect to the downstairs access point and then go into the office upstairs it will not auto connect to the Access point in the office! It will carry on connected to the weaker access point downstairs!

I do apologise for my terminology in these things. I think i may frequently using wrong names for things.
 
One issue I am now having is that I have cloned the SSID and I can see it works. However, say if you connect to the downstairs access point and then go into the office upstairs it will not auto connect to the Access point in the office! It will carry on connected to the weaker access point downstairs!

Yup, I mentioned this in the first part of my answer. There are 3 different ways to fix this and some might not be available to you based on your devices:
  1. Manually disconnect and reconnect the device to force it to pick up the stronger network. Will always work regardless of devices.
  2. Set the connecting device to a "promiscuous" mode. This will tell the device to always search for and connect to the strongest network it has saved. Downside is if you're between 2 equally strong signals you will constantly disconnect and reconnect.
  3. Some routers will have an advanced setting to disconnect connected devices when their strength reaches a threshold. If there isn't another AP to connect to, your device will re-connect to this and get stuck in a loop basically. Only do it if there are enough APs around so there will always be a network above the threshold.
 
or use a wireless lan controller that will force clients to disconnect and drop emitter power and increase emitter power etc to ensure that clients are balanced over your infrastructure.
 
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