NAME

ural — Ralink Technology/MediaTek USB IEEE 802.11b/g wireless network device

SYNOPSIS

ural* at uhub? port ?

DESCRIPTION

The ural driver supports USB 2.0 wireless adapters based on the Ralink RT2500USB chipset.

The RT2500USB chipset is the first generation of 802.11b/g adapters from Ralink. It consists of two integrated chips, an RT2570 MAC/BBP and an RT2526 radio transceiver.

These are the modes the ural driver can operate in:

BSS mode

Also known as infrastructure mode, this is used when associating with an access point, through which all traffic passes. This mode is the default.

IBSS mode

Also known as IEEE ad-hoc mode or peer-to-peer mode. This is the standardized method of operating without an access point. Stations associate with a service set. However, actual connections between stations are peer-to-peer.

Host AP

In this mode the driver acts as an access point (base station) for other cards.

monitor mode

In this mode the driver is able to receive packets without associating with an access point. This disables the internal receive filter and enables the card to capture packets from networks which it wouldn't normally have access to, or to scan for access points.

The ural driver can be configured to use Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA1 and WPA2). WPA2 is the current encryption standard for wireless networks. It is strongly recommended that neither WEP nor WPA1 are used as the sole mechanism to secure wireless communication, due to serious weaknesses. WPA1 is disabled by default and may be enabled using the option "wpaprotos wpa1,wpa2". For standard WPA networks which use pre-shared keys (PSK), keys are configured using the "wpakey" option. WPA-Enterprise networks require use of the wpa_supplicant package. The ural driver relies on the software 802.11 stack for both encryption and decryption of data frames.

The transmit speed is user-selectable or can be adapted automatically by the driver depending on the number of hardware transmission retries.

The ural driver can be configured at runtime with ifconfig(8) or on boot with hostname.if(5).

HARDWARE

The following adapters should work:

EXAMPLES

The following example scans for available networks:

The following hostname.if(5) example configures ural0 to join network “mynwid”, using WPA key “mywpakey”, obtaining an IP address using DHCP:

nwid mynwid wpakey mywpakey
dhcp

The following hostname.if(5) example creates a host-based access point on boot:

mediaopt hostap
nwid mynwid wpakey mywpakey
inet 192.168.1.1 255.255.255.0

DIAGNOSTICS

ural0: device timeout

A frame dispatched to the hardware for transmission did not complete in time. The driver will reset the hardware. This should not happen.

SEE ALSO

arp(4), ifmedia(4), intro(4), netintro(4), usb(4), hostname.if(5), hostapd(8), ifconfig(8)

HISTORY

The ural driver first appeared in OpenBSD 3.7.

AUTHORS

The ural driver was written by Damien Bergamini <damien.bergamini@free.fr>.

CAVEATS

The ural driver supports automatic control of the transmit speed in BSS mode only. Therefore the use of an ural adapter in Host AP mode is discouraged.

Host AP mode doesn't support power saving. Clients attempting to use power saving mode may experience significant packet loss (disabling power saving on the client will fix this).