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CDCE(4)			 BSD Kernel Interfaces Manual		       CDCE(4)

     cdce -- USB Communication Device Class Ethernet driver

     device uhci
     device ohci
     device usb
     device cdce

     The cdce driver provides support for USB Host-to-Host (aka	USB-to-USB)
     and USB-to-Ethernet bridges based on the USB Communication	Device Class
     (CDC) and Ethernet	subclass, including the	following:

     o	 Prolific PL-2501 Host-to-Host Bridge Controller
     o	 Sharp Zaurus PDA
     o	 Terayon TJ-715	DOCSIS Cable Modem

     The USB bridge appears as a regular network interface on both sides,
     transporting Ethernet frames.

     For more information on configuring this device, see ifconfig(8).

     USB 1.x bridges support speeds of up to 12Mbps, and USB 2.0 speeds	of up
     to	480Mbps.

     Packets are received and transmitted over separate	USB bulk transfer end-

     The cdce driver does not support different	media types or options.

     cdce%d: no	union descriptor  The driver couldn't fetch an interface de-
     scriptor from the USB device.  For	a manually added USB vendor/product,
     the CDCE_NO_UNION flag can	be tried to work around	the missing descrip-

     cdce%d: no	data interface
     cdce%d: could not read endpoint descriptor
     cdce%d: unexpected	endpoint
     cdce%d: could not find data bulk in/out  For a manually added USB ven-
     dor/product, these	errors indicate	that the bridge	is not compatible with
     the driver.

     cdce%d: watchdog timeout  A packet	was queued for transmission and	a
     transmit command was issued, however the device failed to acknowledge the
     transmission before a timeout expired.

     cdce%d: no	memory for rx list -- packet dropped!  Memory allocation
     through MGETHDR or	MCLGET failed, the system is running low on mbufs.

     cdce%d: abort/close rx/tx pipe failed
     cdce%d: rx/tx list	init failed
     cdce%d: open rx/tx	pipe failed
     cdce%d: usb error on rx/tx

     arp(4), intro(4), netintro(4), usb(4), ifconfig(8)

     Universal Serial Bus Class	Definitions for	Communication Devices,

     Data sheet	Prolific PL-2501 Host-to-Host Bridge/Network Controller,

     The cdce device driver first appeared in OpenBSD 3.6, NetBSD 3.0 and
     FreeBSD 5.4.

     The cdce driver was written by Craig Boston <>	based
     on	the aue(4) driver written by
     Bill Paul <> and ported	to OpenBSD by
     Daniel Hartmeier <>.

     Many USB devices notoriously fail to report their class and interfaces
     correctly.	 Undetected products might work	flawlessly when	their vendor
     and product IDs are added to the driver manually.

BSD			       October 22, 2004				   BSD


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