====== Wireless (Wifi) Networking ======

===== Roaming =====

http://superuser.com/questions/122441/how-can-i-get-the-same-ssid-for-multiple-access-points

http://support.apple.com/kb/HT4260

In this image, #1 is the primary WAP and the #2's are secondaries:

{{ :networking:wireless_hw_overview.png |Wireless Hardware Overview}}

  - Try to use cabled Ethernet to connect the primary wireless access point (WAP) to the secondary WAP units
  - If you can't use cabled Ethernet, use a separate wireless network for the uplink from the secondaries to the primary
  - If you use a separate wireless uplink, use a different technology
    * 802.11b/g/n for clients
    * 802.11a for uplink
  - Enable NAT on the primary WAP/router that connects to the Internet
    * Optionally enable the DHCP Server function as well
      * Only one DHCP server per subnet
  - Don't use routing or NAT on the secondary WAP units
    * Leave the WAN port empty
    * Or use the WAN port and configure it as bridged mode
  - Use the exact same settings on all wireless access points
    * SSID
    * Security (WPA2-PSK)
    * Password/Pre-Shared Key
  - Set each WAP to a different channel
    * Use non-overlapping and (hopefully) unoccupied channels

===== Performance =====

  - Use the latest APs that support simultaneous dual-band 802.11n technology
    * Supports older 2.4GHz clients
    * And supports newer 5GHz 802.11n clients
  - For older 2.4GHz 802.11n radios, you might configure it for 20MHz (HT20) channels
    * This limits your 802.11n transmission rates in 2.4GHz to ~130mbps instead of 300mbps
    * But leaves some of the band free for things like Bluetooth
  - For newer 5GHz 802.11n radios, you might configure it for wider 40MHz (HT40) channels
    * For maximum throughput
  - If you don't need to support any older 2.4GHz-only devices, use the 5GHz band
    * It is generally less busy
    * And you can use HT40 without starving Bluetooth and other uses
  - When working with 2.4GHz radios:
    * If you don't have a lot of interference, **try using channels 1, 6 and 11**
      * They don't overlap at all
      * Choose channels in increments of three to the next closest access point or interference