NAME

urtwn — Realtek RTL8188CU/RTL8188EU/RTL8188FTV/RTL8192CU/RTL8192EU USB IEEE 802.11b/g/n wireless network device

SYNOPSIS

urtwn* at uhub? port ?

DESCRIPTION

The urtwn driver supports USB 2.0 wireless network devices based on Realtek RTL8188CU, RTL8188CE-VAU, RTL8188EU, RTL8188FTV, RTL8188RU, RTL8192CU and RTL8192EU chipsets.

The RTL8188CU, RTL8188EU and RTL8188FTV are highly integrated 802.11n adapters that combine a MAC, a 1T1R capable baseband and an RF in a single chip. They operate in the 2GHz spectrum only. The RTL8188RU is a high-power variant of the RTL8188CU. The RTL8188CE-VAU is a PCI Express Mini Card adapter that attaches to the USB interface.

The RTL8192CU and RTL8192EU are highly integrated multiple-in, multiple-out (MIMO) 802.11n adapters that combine a MAC, a 2T2R capable baseband and an RF in a single chip. They operate in the 2GHz spectrum only.

These are the modes the urtwn 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.

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 urtwn driver can be configured to use Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA1 and WPA2). WPA2 is currently the most secure encryption standard for wireless networks supported by OpenBSD. 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 urtwn driver can be configured at runtime with ifconfig(8) or on boot with hostname.if(5).

FILES

The adapter needs firmware files to run, which are loaded on demand by the driver when the device is attached:

HARDWARE

The following adapters should work:

EXAMPLES

The following example scans for available networks:

The following hostname.if(5) example configures urtwn0 to join network “mynwid”, using WPA key “mywpakey”, obtaining an IP address using DHCP:

join mynwid wpakey mywpakey
inet autoconf

DIAGNOSTICS

urtwn0: error N, could not read firmware ...

For some reason, the driver was unable to read the microcode file from the filesystem. The file might be missing or corrupted.

urtwn0: 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), ifconfig(8)

HISTORY

The urtwn driver first appeared in OpenBSD 4.9.

AUTHORS

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

CAVEATS

The urtwn driver does not support any of the 802.11n capabilities offered by the adapters. Additional work is required in ieee80211(9) before those features can be supported.