umodem(4)

umodem4

Usb modem support

Usage

umodem* at uhub? ucom* at umodem?

Overview

The umodem driver provides support for USB modems in the Communication Device Class using the Abstract Control Model. These modems are basically standard serial line modems, but they are accessed via USB instead. They support a regular AT command set. The commands can either be multiplexed with the data stream or handled through separate pipes. In the latter case the AT commands have to be given on a device separate from the data device.

The device is accessed through the ucom(4) driver which makes it behave like a tty(4).

Releases

54 releases since OpenBSD 2.8; the text changed 6 times.

  1. 2.8
  2. 2.9
  3. 3.0–3.1
  4. 3.2–3.6
  5. 3.7–4.1
  6. 4.2–4.3
  7. 4.4–8.0

History

The umodem driver appeared in NetBSD 1.5. OpenBSD support was added in OpenBSD 2.7.

Bugs

Only modems with multiplexed commands and data are supported at the moment.

From man 8.0-current-20261101 in OpenBSD 8.0-current (2026-11-01). Parsed by carta from the page's mdoc source.