CxNode (C Node) is a node with a single upstream connection. Most of the time it is a linux or freebsd router or bridge with two wireless interfaces. Alternatively, the upstream interface may be a "tunnel" through the public internet.
Upstream: One interface operating in iBSS mode (also called AdHocMode) is connected via directional antenna to its upstream BxNode. (Alternatively, the upstream connection may be an IpTunnel. While we expect tunnels to be important in early phases, when the wireless network is sparse, we intend to migrate to full wireless connectivity.)
Access Point: The other interface is an AccessPoint or a wireless card operating as an AccessPoint (BSS mode, also called managed mode or InfrastructureMode); it has an omnidirectional antenna that ClientNodes connect to.
The long term plan is to have CxNode have a /24 address range (similar to a class C address) that is assigned to it by its upstream BxNode. Presently the IP address range is assigned by according to the nodes physical location, see IpAllocation..