Ground routing¶

We call "ground routing" the setup where a router running Libre-Mesh is connected via cable(s), eventually through a switch, to some wireless routers running the original firmware in WDS (transparent bridge mode) Ap/Sta mode.

Ground routing is already used in Ninux community (known as Routing a terra) and in Guifi community (known as Supernodos híbridos).

Physical setup¶

There are two physical setup variant usually used:

• each wireless routers in WDS mode is connected via an ethernet cable to a different port of the ground router running Libre-Mesh;
• the wireless routers in WDS mode are connected via an ethernet cable to a switch which is connected with an ethernet cable to a port of the ground router running Libre-Mesh.

First mode have the advantage that doesn't need 802.1q tagged vlan support (on both ground router and wireless routers with WDS) while has the disadvantage that you have to run one cable for each wireless routers with WDS, the second mode has the advantage that you can run just one ethernet cable from your roof switch to your ground router but both ground router and wireless routers with WDS need to support 802.1q tagged vlan in order to avoid layer 2 loops.

Pros and cons of using ground routing in your community¶

Pros:

• separation between routing and radio
  • less load on wireless devices;
  • for working on routing stuff/flashing/doing experiments you work on just one easily accessible device;
• usage of vendor provided wireless drivers
  • could perform differently than ones included in OpenWRT;
  • could support some more features (like dynamic frequency selection or transmit power control) eventually meaning less power consumption;
• wireless routers in WDS mode on roof doesn't need to be supported by OpenWRT/Libre-Mesh but need to support vlan and WDS;
• less devices doing actual routing so less routing data traffic overhead.

Cons:

• another router is needed
  • more money to spend;
  • more energy consumption;
• vendor lock-in because WDS modes from different firmware vendors are not compatible: in order to connect to a node using ground routing with original firmware on antennas you have to buy wireless hardware from the same vendor and use original firmware;
• use of closed source firmware on wireless routers;
• limitation on wireless modes available: usually only access point - station mode is supported from original firmware so no proper mesh (ad-hoc or 802.11s) is possible
  • some devices are more central than others: less decentralization;
  • you have to plan in advance which devices are stations and which is the access point;
  • using ap-sta approach some links are not possible, like sta-sta or ap-ap, that otherwise, using ad-hoc, would be possible; this affects when using omnidirectional or sector antennas while isn't a problem using directive antennas;
  • the stations are going to connect to a specific access point, if this goes down all the stations are isolated, this is a single point of failure;

Configuration¶

TODO

Refer on comments in /etc/config/lime file for configuration.