802.11 a/b/g Wi-Fi Support

Wi-Fi capability is built into the two hc variants of the stack ( io-pkt-v4-hc and io-pkt-v6-hc ). The NetBSD stack includes its own separate 802.11 MAC layer that's independent of the driver. Many other implementations pull the 802.11 MAC inside the driver; as a result, every driver needs separate interfaces and configuration utilities. If you write a driver that conforms to the stack's 802.11 layer, you can use the same set of configuration and control utilities for all wireless drivers.

The networking Wi-Fi solution lets you join or host WLAN (Wireless LAN) networks based on IEEE 802.11 specifications. Using io-pkt, you can:

Ad hoc mode lets you create a wireless network quickly by allowing wireless nodes within range (for example, the wireless devices in a room) to communicate directly with each other without the need for a wireless access point. While being easy to construct, it may not be appropriate for a large number of nodes because of performance degradation, limited range, non-central administration, and weak encryption.

Infrastructure mode is the more common network configuration where all wireless hosts (clients) connect to the wireless network via a WAP (Wireless Access Point). The WAP centrally controls access and authentication to the wireless network and provides access to rest of your network. More than one WAP can exist on a wireless network to service large numbers of wireless clients.

The io-pkt manager supports WEP, WPA, WPA2, or no security for authentication and encryption when acting as the WAP or client. WPA/WPA2 is the recommended encryption protocol for use with your wireless network. WEP isn't as secure as WPA/WPA2 and is known to be breakable. It's available for backward compatibility with already deployed wireless networks.

For information on connecting your client, see " Using wpa_supplicant to manage your wireless network connections " later in this chapter.