PGT(4)

NAME
pgt - Conexant/Intersil Prism GT Full-MAC IEEE 802.11a/b/g wireless network device

SYNOPSIS
pgt* at cardbus?
pgt* at pci?

DESCRIPTION
The pgt driver provides support for Conexant/Intersil GT-series devices which can support the Full-MAC firmware, using the ISL3877, ISL3880, and ISL3890 chips. The pgt driver will not (yet) work on similar devices using the ISL3886 or similar chips which use the Soft-MAC firmware.

These are the modes the pgt 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 pgt driver can be configured to use 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.

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

The pgt 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:

/etc/firmware/pgt-isl3877
/etc/firmware/pgt-isl3890

These firmware files are not free because Conexant 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 can be installed using fw_update(8).

HARDWARE
The following cards are among those supported by the pgt driver:
Card | Chip | Bus
3COM 3CRWE154G72 | ISL3880 | CardBus
D-Link DWL-g650 A1 | ISL3890 | PCI
I-O Data WN-G54/CB | ISL3890 | PCI
I4 Z-Com XG-600 | ISL3890 | PCI
I4 Z-Com XG-900 | ISL3890 | PCI
Intersil PRISM Indigo | ISL3877 | PCI
Intersil PRISM Duette | ISL3890 | PCI
NETGEAR WG511 (Taiwanese, not Chinese) | ISL3890 | CardBus
PLANEX GW-DS54G | ISL3890 | PCI
SMC EZ Connect g 2.4GHz SMC2802W | ISL3890 | PCI
SMC EZ Connect g 2.4GHz SMC2835W-v2 | ISL3890 | CardBus
SMC 2802Wv2 | ISL3890 | PCI
Soyo Aerielink | ISL3890 | CardBus
ZyXEL ZyAIR G-100 | ISL3890 | CardBus

EXAMPLES
The following example scans for available networks:

    # ifconfig pgt0 scan

The following hostname.if(5) example configures pgt0 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:

    mediaopt hostap
    nwid mynwid nwkey mywepkey
    inet 192.168.1.1 255.255.255.0

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

HISTORY
The pgt driver first appeared in OpenBSD 4.0.

AUTHORS
-nosplit The pgt driver was originally written for FreeBSD by Brian Fundakowski, and then rewritten for OpenBSD by Marcus Glocker and Claudio Jeker.

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).