[Berlin-wireless] HowTo: highspeed 5 GHz Backbone

Bluse-Blue h2o-post
Sa Feb 16 12:41:15 CET 2008

Hi Freifunkers,

In our Freifunk mesh, we changed the 5 GHz Backbone setup to 3 stand alone 
performant point to point connections between good freifunk nodes, having 
many 1-hop neighbors.

details of a point-to-point connection:
-> needed hardware:
    -2x ASUS-WL500g Premium
    -2x Atheros miniPCI (successful tested with Gigabyte 101T & Wistron 
    -2x 5GHz Antennas, pigtails & cables

-> needed software:
    -DD-WRT v24RC6.2_atheros_wifi.bin (21.12.2007)
    -settings: WDS AP mode, wlan interfaces unbridged, country settings: 
Finland, outdoor channels enabled, turbo mode on, autorate on, encryption 
does not             work

-> reached results:
    -with the countrycode set to Finland, there is a interference free 
transmission in 3 outdoor channels in turbo mode possible -> good to have 
some point to point     connections to a good central point (a church in our 
    -our 3 installed outdoor links cover a distance from 100m to 500m, all 
links working with 108MBit-96MBit autorate
    -TCP max troughput (one way)= 7,2MByte/sek
    -UDP max troughput (one way)= 7,8 MByte/sek

If you don´t care about using DD-WRT as a firmware, you will get a high 
speed and reasonable point to point connection within your freifunk mesh.
Just connected the WAN Ports of the Freifunk nodes Togehther over the 
bridged DD-WRT 5GHz Routers.

The bottleneck shifts to the Routing performance of the Freifunk nodes. 
Because they are not able to route between WAN and LAN 7,5MByte/sek. So 
about 3,5MByte/sek we achieved. We think the Broadcom switch driver from 
openwrt is not that performant.Any hints ?

Have a nice weekend !

Bye Bluse @freifunk-sundhausen

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