CDCE(4) BSD Kernel Interfaces Manual CDCE(4)NAMEcdce — USB Communication Device Class Ethernet driver
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
Alternatively, to load the driver as a module at boot time, place the
following line in loader.conf(5):
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,
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
Packets are received and transmitted over separate USB bulk transfer end‐
The cdce driver does not support different media types or options.
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
cdce%d: no union descriptor The driver could not 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 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
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 ALSOarp(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
The cdce driver was written by Craig Boston ⟨firstname.lastname@example.org⟩ based
on the aue(4) driver written by Bill Paul ⟨email@example.com⟩ and
ported to OpenBSD by Daniel Hartmeier ⟨firstname.lastname@example.org⟩.
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 September 17, 2005 BSD