Wireless router up to 40 active users

[YeOldeStonecat]

"What are the clients doing" is the first logical question which should have an answer.
You can get pretty much any Stinksys or Nutgear or DStink residential grade wireless router to get a bunch of clients "connected"...and perhaps even browsing the internet. If this is a residential network..fine.

Soon as you step into a business network...this may kick up to laptops and other windows based wireless clients needing connections to a file server, or even greater....running some application from a file server. Or perhaps mobile laptop clients doing a "sync" of their portable database (which could be several hundred megs or more). This is what separates the residential grade toys'r'us wireless routers from the business grade...which, well..businesses typically don't run wireless routers but more dedicated true firewall routers...and multiple wireless access points on the inside. Quick summary...if you have heavy transfers....this is where weaker wireless, which may have allowed many clients to connect and surf the net, will begin to crumble. And you'd want to get more biz grade wireless APs like Ubiquiti, Ruckus, Mimosa, Meraki, etc.

 

[sfx2000]

Some things to consider when trying to put that many clients onto a single AP

• Application(s)
• Clients (Protocol/Frequency, Capabilities)
• Architecture/Infrastructure (MCA, SCA, AP capabilities)
• Infrastructure Configuration
• RF Characteristics of the surrounding area

And this might help to see if one AP can handle the traffic, or more than that...

1. Application Mbps / Device Capability Max Mbps = % of airtime (per device)
2. % of airtime (per device) * # of devices = % of total airtime needed
3. % of total airtimes / .8 (rounded up to whole #) = # of radios
4. of radios / 2 = # of Dual-Band AP's

 

[sfx2000]

Here's a python script that I found some time back... I'm not the author, I believe it is Mike Albano, but not certain...

#!/usr/bin/env python

import math,sys

#### the formula ####
# 1. Application Mbps / Device Capability Max Mbps = % of airtime (per device)
# 2. % of airtime (per device) * # of devices = % of total airtime needed
# 3. % of total airtimes / 80 (rounded up to whole #) = # of radios
# 4.  of radios / 2 = # of AP's
####
# device capability max (called 'max factor') based on your expected max MCS index.
# Default is MCS 5,13 & 21 for 1,2,3 Spatial Stream devices.
# Last updated 2014-08-10 by Mike Albano
####

# define the formula
def df_formula():
  # mult. by 100 to turn result into percent of 100
  # get air-time usage for each device type & chan-width
  app_airtime_20 = (float(app_mbps) / ss_20_max) * 100
  app_airtime_2ss_20 = (float(app_mbps) / two_20_max) * 100
  app_airtime_3ss_20 = (float(app_mbps) / three_20_max) * 100
  app_airtime_40 = (float(app_mbps) / ss_40_max) * 100
  app_airtime_2ss_40 = (float(app_mbps) / two_40_max) * 100
  app_airtime_3ss_40 = (float(app_mbps) / three_40_max) * 100
  # add up the total amount of airtime used by all clients
  device_airtime = (app_airtime_20 * float(ss_devices_20)) + (app_airtime_2ss_20 * float(two_ss_devices_20)) + (app_airtime_3ss_20 * float(three_ss_devices_20)) + (app_airtime_40 * float(ss_devices_40)) + (app_airtime_2ss_40 * float(two_ss_devices_40)) + (app_airtime_3ss_40 * float(three_ss_devices_40))
  #determine # of radios and round up for # of AP's
  radios = device_airtime / 80.0
  aps = math.ceil(radios / 2)
  print "you need %.2f radios or %d dual-band Access Points" % (radios, aps)
  print "Note: this number depends on your spectral re-use. If you can't get more than 3 2.4GHz radios in the area, adjust accordingly."

# Define default Max Mbps (max factor) of devices
ss_20_max = 29.0
two_20_max = 57.0
three_20_max = 86.0
# mult. by 2.09 for 40mhz
ss_40_max = float(2.09 * ss_20_max)
two_40_max = float(2.09 * two_20_max)
three_40_max = float(2.09 * three_20_max)

# Questions/Input from user
app_mbps = raw_input("Application(s) TCP/UDP throughput in Mbps [default 1 ]> ")
if not app_mbps:
  app_mbps = 1.0
chan_width = raw_input("What channel width (20/40) will you be supporting? [default 20] > ")
# if 40MHz chan-width in use, obtain number of capable clients
if chan_width == '40':
  ss_devices_40 = raw_input("How many concurrent 40MHz capable Single Stream devices(eg Smartphones) [default 100] > ")
  if not ss_devices_40:
  ss_devices_40 = 100.0
  two_ss_devices_40 = raw_input("How many concurrent 40MHz capable two Spatial Stream devices(eg tablets) [default 100] > ")
  if not two_ss_devices_40:
  two_ss_devices_40 = 100.0
  three_ss_devices_40 = raw_input("How many concurrent 40MHz capable three Spatial Stream devices(eg laptops)? [default 50] > ")
  if not three_ss_devices_40:
  three_ss_devices_40 = 50.0
elif chan_width != '40':
  ss_devices_40 = 0.0
  two_ss_devices_40 = 0.0
  three_ss_devices_40 = 0.0

# obtain number of 20MHz capable clients
ss_devices_20 = raw_input("How many concurrent 20MHz Single Stream devices(eg Smartphones) [default 100] > ")
if not ss_devices_20:
  ss_devices_20 = 100.0
two_ss_devices_20 = raw_input("How many concurrent 20MHz two Spatial Stream devices(eg tablets)? [default 100] > ")
if not two_ss_devices_20:
  two_ss_devices_20 = 100.0
three_ss_devices_20 = raw_input("How many concurrent 20MHz three Spatial Stream devices(eg laptops)? [default 50] > ")
if not three_ss_devices_20:
  three_ss_devices_20 = 50.0

modify_max = raw_input("Would you like to modify the 'max' factor? Type 'help' for more info [yes,no,help] > ")
if modify_max == 'help':
  print "Default max factor is MCS 5, 13 & 21. You can enter a new value, which changes each clients max TCP/UDP capabilities (based on MCS value). For example, if you enter 0, the new MCS values will be 0, 8 & 16. Assumptiom here is all things being equal, your client MCS values will go up/down together."
  modify_max = raw_input("Would you like to modify the 'max' factor? [yes,no] > ")

if modify_max == 'yes':
  max_factor = raw_input("what would you like the max MCS rate to be? [0-7] > ")
  # change the 'max tcp/udp' values, based on user input
  if max_factor == '0':
  ss_20_max /=  8.0
  two_20_max /=  8.0
  three_20_max /= 8.0
  elif max_factor == '1':
  ss_20_max /= 4.0
  two_20_max /= 4.0
  three_20_max /= 4.0
  elif max_factor == '2':
  ss_20_max /= 3.0
  two_20_max /= 3.0
  three_20_max /= 3.0
  elif max_factor == '3':
  ss_20_max /= 2.0
  two_20_max /= 2.0
  three_20_max /= 2.0
  elif max_factor == '4':
  ss_20_max /= 1.4
  two_20_max /= 1.4
  three_20_max /= 1.4
  elif max_factor == '6':
  ss_20_max *=  1.1
  two_20_max *= 1.1
  three_20_max *= 1.1
  elif max_factor == '7':
  ss_20_max *= 1.2
  two_20_max *= 1.2
  three_20_max *= 1.2
  # mult. by 2.09 for 40mhz
  ss_40_max = float(2.09 * ss_20_max)
  two_40_max = float(2.09 * two_20_max)
  three_40_max = float(2.09 * three_20_max)

  df_formula()
else:
  df_formula()