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NAME

wi — WaveLAN/IEEE, PRISM 2-3, and Spectrum24 IEEE 802.11b wireless network device

SYNOPSIS

# all architectures
wi* at pci?
wi* at pcmcia? function ?
wi* at uhub? port ?

# macppc extra attachment
wi* at macobio?

DESCRIPTION

The wi driver provides support for wireless network adapters based around the Lucent Hermes, Intersil PRISM-2, Intersil PRISM-2.5, Intersil PRISM-3, and Symbol Spectrum24 chipsets. All five chipsets provide a similar interface to the driver.

The wi driver encapsulates all IP and ARP traffic as 802.11 frames, though it can receive either 802.11 or 802.3 frames. Transmit speed is selectable between 1Mbps fixed, 2Mbps fixed, 2Mbps with auto fallback, 5.5Mbps, 8Mbps, or 11Mbps, depending on hardware.

These are the modes the wi 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 as in ad-hoc mode. Cards with very old firmware revisions do not support this mode.

IBSS master

Also know as Host IBSS mode. In this mode the station takes on part of the role of an access point, though traffic does not pass through it to reach the other stations. When a group of stations are operating in IBSS mode, one of them must be the master, specifying the network name of the service set.

Host AP

In this mode the driver acts as an access point (base station) for other cards. Only cards based on the Intersil chipsets support this mode. Furthermore, this mode is not supported on USB devices.

ad-hoc mode

More accurately known as ad-hoc demo mode. This mode does not require an access point; the adapter communicates with other ad-hoc stations within range on a peer-to-peer basis. This mode is not specified by the IEEE 802.11 standard and there may be problems interoperating with adapters manufactured by different vendors.

The wi driver can be configured to use both software and hardware Wired Equivalent Privacy (WEP). It is strongly recommended that WEP not be used as the sole mechanism to secure wireless communication, due to serious weaknesses in it.

The Lucent WaveLAN/IEEE Silver and Gold cards as well as the Intersil and Symbol cards have support for WEP encryption. The WaveLAN Gold as well as newer Intersil and Symbol cards support 104-bit keys, the others only accept 40-bit keys. The Lucent WaveLAN/IEEE Bronze cards do not support WEP at all. See also CAVEATS below.

In BSS mode, the driver supports powersave mode, which can be enabled via ifconfig(8).

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

HARDWARE

Cards supported by the wi driver come in a variety of packages, though the most common are of the PCMCIA type. In many cases, the PCI version of a wireless card is simply a PCMCIA card bundled with a PCI adapter. The PCI adapters come in two flavors: true PCMCIA bridges and dumb PCMCIA bridges. A true PCMCIA bridge (such as those sold by Lucent) will attach as a real PCMCIA controller. The wireless card will then attach to the PCMCIA bus. Wireless cards in PCMCIA slots may be inserted and ejected on the fly. A dumb bridge, on the other hand, does not show up as a true PCMCIA bus. The wireless card will simply appear to the host as a normal PCI device and will not require any PCMCIA support. Cards in this type of adapter should only be removed when the machine is powered down.

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

Note that some of the PRISM-II adapters only work at 3.3V, hence cardbus(4) support is required for those cards to set VCC correctly, even though they are really 16-bit cards.

USB support is still experimental and the device may stop functioning during normal use. Resetting the device by configuring the interface down and back up again will normally reactivate it.

Several vendors sell PCI adapters built around the PLX Technology 9050 or 9052 chip. The following such adapters are supported or expected to work:

EXAMPLES

The following example scans for available networks:

The following hostname.if(5) example configures wi0 to join network “mynwid”, using WEP key “mywepkey”, obtaining an IP address using DHCP:

nwid mynwid nwkey mywepkey inet autoconf

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

inet 192.168.1.1 255.255.255.0 mediaopt hostap nwid mynwid nwkey mywepkey

DIAGNOSTICS

wi0: init failed

The WaveLAN card failed to come ready after an initialization command was issued.

wi0: failed to allocate N bytes on NIC

The driver was unable to allocate memory for transmit frames in the NIC's on-board RAM.

wi0: device timeout

The WaveLAN failed to generate an interrupt to acknowledge a transmit command.

SEE ALSO

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

HCF Light programming specification.

HISTORY

The wi device driver first appeared in FreeBSD 3.0. OpenBSD support was added in OpenBSD 2.6.

AUTHORS

The wi driver was written by Bill Paul <wpaul@ctr.columbia.edu> and ported to OpenBSD by Niklas Hallqvist <niklas@appli.se>.

CAVEATS

The original Lucent WaveLAN cards usually default to channel 3; newer cards use channel 10 by default. Non-Lucent cards vary, for instance the Addtron cards use channel 11 by default. See ifconfig(8) for information on how to change the channel.

Not all 3.3V wi PCMCIA cards work.

IBSS creation does not currently work with Symbol cards.

The host-based access point mode on the Intersil PRISM cards has bugs when used with firmware versions prior to 0.8.3 and is completely unusable with firmware versions prior to 0.8.0 and 1.4.0-1.4.2.

Software WEP is currently only supported in Host AP and BSS modes. Furthermore, software WEP is currently incapable of decrypting fragmented frames. Lucent-based cards using firmware 8.10 and above fragment encrypted frames sent at 11Mbps. To work around this, Lucent clients with this firmware revision connecting to a Host AP server should use a 2Mbps connection or upgrade their firmware to version 8.72.

Host AP mode doesn't support WDS.

Support for USB devices is buggy. Host AP mode and AP scanning are not currently supported with USB devices.