NAME    [Toc]    [Back]

     cdce - USB Communication Device Class Ethernet driver

SYNOPSIS    [Toc]    [Back]

     cdce*  at uhub? port ?

DESCRIPTION    [Toc]    [Back]

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

     +o   Prolific PL-2501
     +o   Sharp Zaurus

     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 endpoints.


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

DIAGNOSTICS    [Toc]    [Back]

     cdce%d:  no  union  descriptor  The driver couldn't fetch an
interface descriptor
 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 vendor/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

SEE ALSO    [Toc]    [Back]

     arp(4), intro(4), netintro(4), usb(4),  hostname.if(5),  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    [Toc]    [Back]

     The cdce device driver first appeared in OpenBSD 3.6.

AUTHORS    [Toc]    [Back]

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

CAVEATS    [Toc]    [Back]

     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.

OpenBSD      3.6                           July      20,     2004