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NAME

acx — TI ACX100/ACX111 IEEE 802.11a/b/g wireless network device

SYNOPSIS

acx* at cardbus?
acx* at pci?

DESCRIPTION

The acx driver provides support for TI TNETW1100/TNETW1100B (ACX100) and TNETW1130 (ACX111) based PCI/CardBus network adapters.

The ACX100A and ACX100B are first generation 802.11b devices from TI. The ACX111 is a second generation device which supports 802.11b/g and in some cases 802.11a.

These are the modes the acx 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 acx driver can be configured to use Wired Equivalent Privacy (WEP) in software for ACX111 or in hardware for ACX100. It is strongly recommended that WEP not be used as the sole mechanism to secure wireless communication, due to serious weaknesses in it.

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

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

FILES

The driver needs a set of firmware files which are loaded when an interface is brought up:

These firmware files are not free because TI refuses to grant distribution rights. In fact they have rebuffed thousands of attempts to start a dialogue on this issue. As a result, even though OpenBSD includes the driver, the firmware files cannot be included and users have to download these files on their own.

A prepackaged version of the firmware, designed to be used with pkg_add(1), can be found at:

http://firmware.openbsd.org/firmware/acx-firmware-1.4.tgz

HARDWARE

The following cards are among those supported by the acx driver:

EXAMPLES

The following hostname.if(5) example configures acx0 to join whatever network is available on boot, using WEP key “0x1deadbeef1”, channel 11, obtaining an IP address using DHCP:

dhcp NONE NONE NONE nwkey 0x1deadbeef1 chan 11

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

inet 192.168.1.1 255.255.255.0 NONE media autoselect \
	mediaopt hostap nwid my_net chan 11

Configure acx0 for WEP, using hex key “0x1deadbeef1”:

# ifconfig acx0 nwkey 0x1deadbeef1

Return acx0 to its default settings:

# ifconfig acx0 -bssid -chan media autoselect \
	nwid "" -nwkey

Join an existing BSS network, “my_net”:

# ifconfig acx0 192.168.1.1 netmask 0xffffff00 nwid my_net

SEE ALSO

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

HISTORY

The acx driver first appeared in OpenBSD 4.0.

AUTHORS

The acx driver was written by Sepherosa Ziehau. The manual page was written by Sascha Wildner. Both are based on the http://wlan.kewl.org project team's original code.

The hardware specification was reverse engineered by the good folks at http://acx100.sourceforge.net. Without them this driver would not have been possible.

CAVEATS

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).