Connect more than 40 clients to Netgear WNR2000v5

Question

The 802.11 protocol allows up to 2007 clients per BSSID (most single-band APs like your WNR2000v5 have a single BSSID). If a given AP has a hard limit below that, it's usually due to managing the per-device, per-session encryption keys required by WPA2 (or WPA for that matter, but no one should keep original WPA enabled anymore). So one thing to try if your only goal is to connect as many clients as possible is to disable wireless security (it's not worth going down to WEP as WEP is not very secure).

Another thing that can limit simultaneous clients is just completely running out of available airtime. There are many things you can do to free up airtime:

Switch your AP to a clean channel, or move your setup to somewhere away from all other 2.4GHz interference. Use true a spectrum analyzer such as a Wi-Spy to find non-Wi-Fi interference sources such as cordless phones, microwave ovens, baby monitors, wireless webcams/security cams, Wii remotes, Bluetooth devices, and non-Bluetooth 2.4GHz wireless keyboards and mice, 2.4GHz wireless subwoofers or other speakers, etc., and switch them off. Speaking of Bluetooth, disable Bluetooth on all your mobile devices, laptops, keyboards, mice, etc. Also note that for your AP to hit 300Mbps in 2.4GHz, it's using 40MHz-wide channels, so if you put it on channel 1, it's really using channels 1 and 5 bonded together, and with the way 2.4GHz Wi-Fi channels overlap, you don't want to see any other Wi-Fi devices on any channel below channel 10.
Use only client devices capable of hitting the top data rate of your AP, so that they're all able to use airtime the most efficiently. In your case this means devices that support 802.11n with 40MHz-wide channels (HT40) in 2.4GHz, 2x2:2 (2 spatial streams), and short guard intervals. You have to do all those things at the same time to use the 300Mbps data rate in 2.4GHz. Apple doesn't like doing 40MHz-wide channels in 2.4GHz because it doesn't leave enough room for Bluetooth, so Apple devices only do 20MHz-wide channels in 2.4GHz, so don't use any Apple devices for this test.
Make sure all your devices are close enough to the AP to get the top data rate your AP supports. This usually means putting them where they get -40 to -60dBm RSSI, which probably within ~20m of the AP. But don't put them TOO close to the AP or to each other, or they will overload each others' radios' front ends (think about having someone shouting in your ear while you're trying to listen to a quiet lecturer across the room).
Minimize multicasts (which includes broadcasts). In 802.11, multicasts have to be sent at a low data rate that everyone can receive. Many 2.4GHz APs default to sending multicasts at 1Mbps. That means that if your AP was connected to a corporate gigabit Ethernet office LAN where just 0.1% (one one-thousandth of the total bandwidth) of the LAN was multicast, those multicasts would try to take up 100% of your Wi-Fi airtime. So if this device has to be connected to an Ethernet LAN, make sure there are no multicasts/broadcasts on that LAN, or put the AP in NAT gateway mode so it won't bridge multicasts/broadcasts from the WAN or LAN to the WLAN. Make sure your wireless client devices aren't sending a lot of multicasts/broadcasts either.

Without knowing the exact point of the test you're trying to conduct, I realize some of these suggestions may not be practical for you as they may work against the point of your test. But I thought I'd put it all out there to help you figure it out for yourself.

Answer 1

The 802.11 protocol allows up to 2007 clients per BSSID (most single-band APs like your WNR2000v5 have a single BSSID). If a given AP has a hard limit below that, it's usually due to managing the per-device, per-session encryption keys required by WPA2 (or WPA for that matter, but no one should keep original WPA enabled anymore). So one thing to try if your only goal is to connect as many clients as possible is to disable wireless security (it's not worth going down to WEP as WEP is not very secure).

Another thing that can limit simultaneous clients is just completely running out of available airtime. There are many things you can do to free up airtime:

Switch your AP to a clean channel, or move your setup to somewhere away from all other 2.4GHz interference. Use true a spectrum analyzer such as a Wi-Spy to find non-Wi-Fi interference sources such as cordless phones, microwave ovens, baby monitors, wireless webcams/security cams, Wii remotes, Bluetooth devices, and non-Bluetooth 2.4GHz wireless keyboards and mice, 2.4GHz wireless subwoofers or other speakers, etc., and switch them off. Speaking of Bluetooth, disable Bluetooth on all your mobile devices, laptops, keyboards, mice, etc. Also note that for your AP to hit 300Mbps in 2.4GHz, it's using 40MHz-wide channels, so if you put it on channel 1, it's really using channels 1 and 5 bonded together, and with the way 2.4GHz Wi-Fi channels overlap, you don't want to see any other Wi-Fi devices on any channel below channel 10.
Use only client devices capable of hitting the top data rate of your AP, so that they're all able to use airtime the most efficiently. In your case this means devices that support 802.11n with 40MHz-wide channels (HT40) in 2.4GHz, 2x2:2 (2 spatial streams), and short guard intervals. You have to do all those things at the same time to use the 300Mbps data rate in 2.4GHz. Apple doesn't like doing 40MHz-wide channels in 2.4GHz because it doesn't leave enough room for Bluetooth, so Apple devices only do 20MHz-wide channels in 2.4GHz, so don't use any Apple devices for this test.
Make sure all your devices are close enough to the AP to get the top data rate your AP supports. This usually means putting them where they get -40 to -60dBm RSSI, which probably within ~20m of the AP. But don't put them TOO close to the AP or to each other, or they will overload each others' radios' front ends (think about having someone shouting in your ear while you're trying to listen to a quiet lecturer across the room).
Minimize multicasts (which includes broadcasts). In 802.11, multicasts have to be sent at a low data rate that everyone can receive. Many 2.4GHz APs default to sending multicasts at 1Mbps. That means that if your AP was connected to a corporate gigabit Ethernet office LAN where just 0.1% (one one-thousandth of the total bandwidth) of the LAN was multicast, those multicasts would try to take up 100% of your Wi-Fi airtime. So if this device has to be connected to an Ethernet LAN, make sure there are no multicasts/broadcasts on that LAN, or put the AP in NAT gateway mode so it won't bridge multicasts/broadcasts from the WAN or LAN to the WLAN. Make sure your wireless client devices aren't sending a lot of multicasts/broadcasts either.

Without knowing the exact point of the test you're trying to conduct, I realize some of these suggestions may not be practical for you as they may work against the point of your test. But I thought I'd put it all out there to help you figure it out for yourself.

Connect more than 40 clients to Netgear WNR2000v5

答案1

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