Increasing number of simultaneous wifi connections

[kumar123]

I have a TP Link ADSL TD-W8961N wifi modem. It allows to connect between 15 to 20 concurrent wifi connections. I would like to have this number increased to over 30 wireless devices. I have an RT-N12 router from Asus. Can I use this router to increase the number of simultaneous wireless connections by turning off its DHCP or some other way?

Thanks.

 

[bicycle_repair_man]

Assuming that the N12 supports the extra amount of concurrent connections you need, yes, it's certainly possible.

What you need to do is disable the DHCP and DNS servers on the N12 (assuming the W8961N will do it) and give it a static IP address. The default gateway needs to be the IP address of the W8961N.

Alternatively, if the W8961N has a mode to enable it as a wireless access point, just go with that.

 

[kumar123]

I really can't say how many connections N12 can handle simultaneously. However, let us say it can support 15 or more devices at the same time. Now, let the IP address of W8961N be 192.168.1.1 and its DHCP starts at 192.168.1.100. So, shall I keep the IP of N12 as 192.168.1.2 and disable its DHCP? One more thing, I just noticed that N12 has an Access Point mode. Shall I enable this mode and everything will be set automatically?

Thanks.

 

[bill001g]

AP mode is pretty much the same thing as turning off the DHCP. It just allows you to cable to the wan port rather than the lan. You would still assign it 192.168.1.2 like you propose.

Using another route/AP does increase the number of wireless devices you can have but it is not as simple as that. There is a limited amount of radio bandwidth. On the 2.4g band there is only 60mhz of bandwidth. Generally this is broken into 3 20mhz parts. This is what channels 1,6,11 represent.

Problem is when you set the router to run the 300m speed it wants to use 40mhz. If you try to run 2 wireless devices at 300m you need 80mhz and there is only 60mhz so you must overlap them which causes interference and both session run slower.

So the simplest option is to force both your devices to run only 20mhz which will limit your top speed to 150m (still likely much faster than your isp). You could the assign one device to say channel 1 and the other device to say channel 11. Unfortunately it is highly likely you have neighbors trying to use the bandwidth also so you will have to see which of the 3 channels is best for each device
Since you are using ADSL for your internet connection you will likely be bottlenecked by that very quickly trying to run that many users even if they were all connected via ethernet.

 

[kumar123]

AP mode is pretty much the same thing as turning off the DHCP. It just allows you to cable to the wan port rather than the lan. You would still assign it 192.168.1.2 like you propose.

Using another route/AP does increase the number of wireless devices you can have but it is not as simple as that. There is a limited amount of radio bandwidth. On the 2.4g band there is only 60mhz of bandwidth. Generally this is broken into 3 20mhz parts. This is what channels 1,6,11 represent.

Problem is when you set the router to run the 300m speed it wants to use 40mhz. If you try to run 2 wireless devices at 300m you need 80mhz and there is only 60mhz so you must overlap them which causes interference and both session run slower.

So the simplest option is to force both your devices to run only 20mhz which will limit your top speed to 150m (still likely much faster than your isp). You could the assign one device to say channel 1 and the other device to say channel 11. Unfortunately it is highly likely you have neighbors trying to use the bandwidth also so you will have to see which of the 3 channels is best for each device. Since you are using ADSL for your internet connection you will likely be bottlenecked by that very quickly trying to run that many users even if they were all connected via ethernet.

Thanks for your detailed response. There are only a few wifi devices in the nearby surrounding so it is not likely to create any sort of issue. Nevertheless, I am going to configure both the devices just as you described. If N12 is set to act as an AP and the cable is to be inserted into the WAN port then where is the need to change its IP to 192.168.1.2 because it's the LAN IP and we are not using ethernet ports at all? Am I missing something? Also, when in AP mode, do I also need to turn off DHCP manually? And, is it possible to keep one SSIDs in both the devices in different channels? Will it offer seamless connectivity?

Thanks

 

[bill001g]

To a point it depends on the device. Most times you set the ip on the lan interface but some I have seen routers that force you to put the ip in the wan interface when you change it to ap/bridge mode. You need to put the IP someplace to make sure you can configure it.

Most times turning on the AP mode disables the dhcp for you automatically.

Keeping 1 ssid or using multiple is choice you have to make. You will never get seamless roaming between the devices.

If you use the same SSID it will switch over by itself but it is really stupid. It pretty much does not even look for another ap to connect to until the signal is unusable. You can connect to the main router walk over and put the laptop directly on top of the other AP and it will not switch if it thinks the signal is "good enough". To a small extent you can change this signal level in the nic settings but then you risk it constantly shifting back and forth.

Some people would rather deal with the manual switching when you have 2 different SSID than hoping the automatic ones works. Many times you turn it off and back on even with the same ssid just to force it to switch.

 

[kumar123]

Having configured both the devices as described here, the simultaneous client number increased to 31- 32. Even this number is short. Now, I would like to have it increased to minimum of 50 and scalable to up to or more than 100 in the future. I have an office measuring 25 feet x 20 feet where I need this setup. I would really appreciate if anyone could suggest a suitable device - even enterprise grade - to meet this requirement.

Any help will be greatly appreciated.

Thanks.

 

[bill001g]

You can look at the ubiquiti line of AP. The number of connections per AP is not related to the brand it is related to the radio bandwidth. Cisco does sell ap that have 3 2.4g radios and 3 5g radios in one box but it costs more than 3 dual band AP and really that is all you are doing.

The main thing with ubiquiti is they give their management software away for free. It makes planning and maintaining multiple AP easier.

What you generally do in a high density office area is put in say 3 AP running on channels 1,6,11 right next to each other. This might run 30 people. You then turn the power down on the AP so the coverage is less. You move down the building a bit and put in another group of 3 adjusting the power on the AP to try to balance. You would still have to find a way to split the users equally between the 3 in one group.

Now if money is no object both cisco and aviaya sell high end systems that let you dynamically control your AP load. It works best if you load their custom wireless drivers on the clients so you can force which ap they connect to. It also allows for seamless roaming. The huge problem is just the controller pc/server costs as much as a nice car.

 

[kumar123]

Thanks for your quick reply. I want to do away with this Asus router altogether and looking for one device which can handle as many as 100 connections. I have already tried lowering antenna power to minimum but since the office area is small having virtually no obstruction, it is able to cover entire office with very little loss of signal. So, as suggested by you, both devices were configured with non-overlapping channels. It is because of this I want to have single point solution managing all the wireless devices. As for the budget, although it is not allocated, I guess it shouldn't cross $500 (+/- 50$!). Any suggestion?

Thank you.

 

[bill001g]

Finding a device that has it all in one box tends to not a common product. Cisco has stopped selling the ones I used to use and I can not even find the old links. Most people use multiple simple AP mounted next to each other.

This is a example from avaya. Avaya is going to be the most expensive brand there is, the only ones I have used are ones we got when we acquired companies and only used them until we could replace them with something cheaper. They were very nice systems the yearly maintenance was above what management wanted to pay.

www.avaya.com/usa/documents/avaya-wlan-9100-series-dn7647.pdf

Something like the 9173 is what you are looking for.

This is another link for this type of device....I have no idea about this company only used as a example.

http://www.extricom.com/category/access-points

Although it would be very nice to have one box that does it all you are going to pay a lot of money for that nicety