NAME
cdce —
USB Communication Device Class Ethernet
device
SYNOPSIS
cdce* at uhub?
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:
- Acer Labs USB 2.0 Data Link
- Dell Wireless 5530
- Dell Wireless 5540
- FRITZ!Box Fon ata 1020
- G.Mate YP3X00
- Lenovo ThinkPad USB 3.0 Ethernet adapter (FRU 03X6903)
- Motorola USBNET
- NetChip EthernetGadget
- Prolific PL-2501
- Sony Ericsson K610i
- Sony Ericsson F3705g
- Yota LU156
- ZTE MF831 LTE USB modem
- ZTE MF920V portable LTE WiFi router
- Zyxel P-971M
The USB bridge appears as a regular network interface on both sides, transporting Ethernet frames. 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. For more information on configuring this device, see
ifconfig(8).
DIAGNOSTICS
- cdce0: extra ethernet descriptor
- There is more than one Ethernet descriptor.
- cdce0: no data interface
- The data interface announced by the union descriptor cannot be found.
- cdce0: no descriptor for interrupt endpoint N
- cdce0: interface alternate setting N failed
- cdce0: no descriptor for bulk endpoint N
- cdce0: 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.
- cdce0: 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.
- cdce0: no memory for rx list -- packet dropped!
- Memory allocation through MGETHDR or MCLGET failed, the system is running low on mbufs.
- cdce0: abort/close rx/tx/interrupt pipe failed
- cdce0: rx/tx list init failed
- cdce0: open rx/tx/interrupt pipe failed
- cdce0: usb error on rx/tx
SEE ALSO
arp(4), intro(4), netintro(4), usb(4), hostname.if(5), ifconfig(8)
Universal Serial Bus Class Definitions for Communication Devices, https://www.usb.org/document-library/class-definitions-communication-devices-12.
Data sheet Prolific PL-2501 Host-to-Host Bridge/Network Controller.
HISTORY
The cdce device driver first appeared in
OpenBSD 3.6.
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 vendor and product IDs are added to the driver manually.