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CDCE(4) 		     Kernel Interfaces Manual			 CDCE(4)

NAME
     cdce -- USB Communication Device Class Ethernet driver

SYNOPSIS
     To compile this driver into the kernel, place the following lines in your
     kernel configuration file:

	   device uhci
	   device ohci
	   device usb
	   device cdce

     Alternatively, to load the driver as a module at boot time, place the
     following line in loader.conf(5):

	   if_cdce_load="YES"

DESCRIPTION
     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.

     The USB bridge appears as a regular network interface on both sides, trans-
     porting 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-
     points.

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

HARDWARE
     The following devices are supported by the cdce driver:

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

DIAGNOSTICS
     cdce%d: no union descriptor  The driver could not 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 descriptor.

     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 trans-
     mit command was issued, however the device failed to acknowledge the trans-
     mission 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

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

     Universal	 Serial   Bus	Class  Definitions  for  Communication	Devices,
     http://www.usb.org/developers/devclass_docs/usbcdc11.pdf.

     Data  sheet  Prolific  PL-2501  Host-to-Host   Bridge/Network   Controller,
     http://tech.prolific.com.tw/visitor/fcabdl.asp?fid=20679530.

HISTORY
     The  cdce	device	driver	first  appeared  in  OpenBSD 3.6, NetBSD 3.0 and
     FreeBSD 6.0.

AUTHORS
     The cdce driver was written by Craig Boston <craig@tobuj.gank.org> based on
     the aue(4) driver written by Bill Paul <wpaul@windriver.com> and ported  to
     OpenBSD by Daniel Hartmeier <dhartmei@openbsd.org>.

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

FreeBSD 9.1		       September 17, 2005			 CDCE(4)

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