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RUM(4) Kernel Interfaces Manual RUM(4)


rumRalink Technology USB IEEE 802.11a/b/g wireless network device


rum* at uhub? port ?


The rum driver supports USB 2.0 wireless adapters based on the Ralink RT2501USB and RT2601USB chipsets.

The RT2501USB chipset is the second generation of 802.11a/b/g adapters from Ralink. It consists of two integrated chips, an RT2571W MAC/BBP and an RT2528 or RT5226 radio transceiver.

The RT2601USB chipset consists of two integrated chips, an RT2671 MAC/BBP and an RT2527 or RT5225 radio transceiver. This chipset uses the MIMO (multiple-input multiple-output) technology with multiple antennas to extend the operating range of the adapter and to achieve higher throughput. MIMO is the basis of the forthcoming IEEE 802.11n standard.

These are the modes the rum 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.

rum supports software WEP. Wired Equivalent Privacy (WEP) is the de facto encryption standard for wireless networks. It can be typically configured in one of three modes: no encryption; 40-bit encryption; or 104-bit encryption. Unfortunately, due to serious weaknesses in WEP protocol it is strongly recommended that it not be used as the sole mechanism to secure wireless communication. WEP is not enabled by default.


The rum driver can be configured at runtime with ifconfig(8) or on boot with ifconfig.if(5) using the following parameters:
bssid bssid
Set the desired BSSID.
Unset the desired BSSID. The interface will automatically select a BSSID in this mode, which is the default.
chan n
Set the channel (radio frequency) to be used by the driver based on the given channel ID n.
Unset the desired channel to be used by the driver. The driver will automatically select a channel in this mode, which is the default.
media media
The rum driver supports the following media types:

Enable autoselection of the media type and options.
Set 802.11b DS 1Mbps operation.
Set 802.11b DS 2Mbps operation.
Set 802.11b DS 5.5Mbps operation.
Set 802.11b DS 11Mbps operation.
Set 802.11a/g OFDM 6Mbps operation.
Set 802.11a/g OFDM 9Mbps operation.
Set 802.11a/g OFDM 12Mbps operation.
Set 802.11a/g OFDM 18Mbps operation.
Set 802.11a/g OFDM 24Mbps operation.
Set 802.11a/g OFDM 36Mbps operation.
Set 802.11a/g OFDM 48Mbps operation.
Set 802.11a/g OFDM 54Mbps operation.
mediaopt opts
The rum driver supports the following media options:

Select Host AP operation.
Select IBSS operation.
Select monitor mode.
-mediaopt opts
Disable the specified media options on the driver and return it to the default mode of operation (BSS).
mode mode
The rum driver supports the following modes:

Force 802.11a operation.
Force 802.11b operation.
Force 802.11g operation.
nwid id
Set the network ID. The id can either be any text string up to 32 characters in length, or a series of hexadecimal digits up to 64 digits. An empty id string allows the interface to connect to any available access points. By default the rum driver uses an empty string. Note that network ID is synonymous with Extended Service Set ID (ESSID).
nwkey key
Enable WEP encryption using the specified key. The key can either be a string, a series of hexadecimal digits (preceded by ‘0x’), or a set of keys of the form “n:k1,k2,k3,k4”, where ‘n’ specifies which of the keys will be used for transmitted packets, and the four keys, “k1” through “k4”, are configured as WEP keys. If a set of keys is specified, a comma (‘,’) within the key must be escaped with a backslash. Note that if multiple keys are used, their order must be the same within the network. rum is capable of using both 40-bit (5 characters or 10 hexadecimal digits) or 104-bit (13 characters or 26 hexadecimal digits) keys.
Disable WEP encryption. This is the default mode of operation.


The following firmware file is loaded when an interface is brought up:

See firmload(9) for how to change this.


The following adapters should work:

Airlink101 AWLL5025
ASUS WL-167g ver 2
Belkin F5D7050 ver 3
Belkin F5D9050 ver 3
CNet CWD-854 ver F
Conceptronic C54RU ver 2
D-Link DWL-G122 rev C1
D-Link WUA-1340
Edimax EW-7318USG
Gigabyte GN-WB01GS
Hawking HWUG1
LevelOne WNC-0301USB
Linksys WUSB54G rev C
Planex GW-USMM
Senao NUB-3701
Sitecom WL-113 ver 2
Sitecom WL-172


The following ifconfig.if(5) example configures rum0 to join whatever network is available on boot, using WEP key “0x1deadbeef1”, channel 11:

inet netmask nwkey 0x1deadbeef1 chan 11

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

inet netmask media autoselect \ 
	mediaopt hostap nwid my_net chan 11

Configure rum0 for WEP, using hex key “0x1deadbeef1”:

# ifconfig rum0 nwkey 0x1deadbeef1

Return rum0 to its default settings:

# ifconfig rum0 -bssid -chan media autoselect \ 
	nwid "" -nwkey

Join an existing BSS network, “my_net”:

# ifconfig rum0 netmask 0xffffff00 nwid my_net


rum%d: failed loadfirmware of file %s
For some reason, the driver was unable to read the microcode file from the filesystem. The file might be missing or corrupted.
rum%d: could not load 8051 microcode
An error occurred while attempting to upload the microcode to the onboard 8051 microcontroller unit.
rum%d: 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.


The rum driver first appeared in NetBSD 4.0 and OpenBSD 4.0.


The rum driver was written by Niall O'Higgins <> and Damien Bergamini <>.


The rum driver supports automatic control of the transmit speed in BSS mode only. Therefore the use of a rum adapter in Host AP mode is discouraged.
February 7, 2007 NetBSD 7.0