CDCE(4) FreeBSD Kernel Interfaces Manual CDCE(4)
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:
o Acer Labs USB 2.0 Data Link
o Dell Wireless 5530
o Dell Wireless 5540
o FRITZ!Box Fon ata 1020
o G.Mate YP3X00
o Lenovo ThinkPad USB 3.0 Ethernet adapter (FRU 03X6903)
o Motorola USBNET
o NetChip EthernetGadget
o Prolific PL-2501
o Sony Ericsson K610i
o Sony Ericsson F3705g
o Yota LU156
o ZTE MF831 LTE USB modem
o ZTE MF920V portable LTE WiFi router
o 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 <
[email protected]> based
on the aue(4) driver written by Bill Paul <
[email protected]> and
ported to OpenBSD by Daniel Hartmeier <
[email protected]>.
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.
FreeBSD 14.1-RELEASE-p8 September 10, 2022 FreeBSD 14.1-RELEASE-p8