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

NAME

     cdce -- USB Communication Device Class Ethernet driver

SYNOPSIS

     cdce*  at uhub? port ?

DESCRIPTION

     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	 Acer Labs USB 2.0 Data Link
     o	 G.Mate YP3X00
     o	 Motorola USBNET
     o	 NetChip EthernetGadget
     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

     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

     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 and NetBSD 3.0.

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 correctly.	Undetected products might work flawlessly when their ven-
     dor and product IDs are added to the driver manually.

BSD
								   June 7, 2011 							       BSD