UMSM(4)

💖 UMSM(4) — the `umsm` manual, bestie edition 💖

okay so this is the page for umsm, which in the Kernel Interfaces Manual universe is literally the Qualcomm MSM modem device driver. yes it's a mouthful. no i will not be shortening it. sit down, grab a strawberry 🍓, we're learning about modems.

✨ SYNOPSIS ✨

umsm* at uhub?
ucom* at umsm?

that's it. that's the whole vibe. umsm attaches at uhub? and ucom* attaches at umsm?. slay. 💅

🦋 DESCRIPTION 🦋

the umsm driver supports Qualcomm MSM modem adapters. the MSM chipset lives inside EVDO, UMTS and LTE capable modems — like, the whole spectrum of "yes i have signal, no you can't have any". typically these are CardBus and PCI Express Mini Cards that incorporate a USB controller with the actual device attached to it. nesting doll energy fr fr 🪆

the following devices are known to work with the umsm driver (device — bus, no cap):

AirPrime PC5220 — CardBus
Alcatel One Touch X060 — USB
Alcatel One Touch X200 — USB
Alcatel One Touch X210 — USB
Alcatel One Touch X220 — USB
AnyDATA ADU-500A — USB
AnyDATA ADU-E100H — USB
AnyDATA A2502 — USB
C-motech CNU 680 — USB
Emobile D01HW (Huawei OEM) — USB
Emobile D02HW (Huawei OEM) — USB
Emobile D12HW (Huawei OEM) — USB
Emobile D22HW (Huawei OEM) — USB
Emobile D31HW (Huawei OEM) — USB
Emobile H12HW (Huawei OEM) — USB
Emobile D21LC (longcheer OEM) — USB
Huawei Mobile E156G — USB
Huawei Mobile E160E — USB
Huawei Mobile E161 — USB
Huawei Mobile E160g — USB
Huawei Mobile E1692 — USB
Huawei Mobile E172 — USB
Huawei Mobile E173 — USB
Huawei Mobile E173s — USB
Huawei Mobile E180 — USB
Huawei Mobile E181 — USB
Huawei Mobile E182 — USB
Huawei Mobile E220 — USB
Huawei Mobile E303 — USB
Huawei Mobile E352 — USB
Huawei Mobile E353 — USB
Huawei Mobile E392 — USB
Huawei Mobile E510 — USB
Huawei Mobile E1550 — USB
Huawei Mobile E1750 — USB
Huawei Mobile E1752 — USB
Huawei Mobile E1820 — USB
Huawei Mobile E3372 — USB
Huawei Mobile EM770W — PCI Express Mini Card
Huawei Mobile K4510 — USB
Huawei Mobile K4511 — USB
Huawei Mobile Connect E169g — USB
Huawei Mobile Connect E618 — USB
Huawei Mobile Connect E620 — USB
IIJMobile 120FU (ZTE OEM) — USB
Kyocera KPC650 — CardBus
Medion Mobile S4012 (Huawei E1550 OEM) — USB
Medion Mobile S4222 (MediaTek OEM) — USB
Novatel Wireless ES620 — USB
Novatel Wireless Ovation U727 — USB
Novatel Wireless U760 — USB
NTT DoCoMo A2502 — USB
ONDA Communication H600 — CardBus
ONDA Communication MSA110UP — USB
Option GlobeSurfer iCON 7.2 — USB
Option GlobeTrotter 3G+ — CardBus
Option GlobeTrotter 3G Quad — CardBus
Option GlobeTrotter 3G Quad Plus — CardBus
Option GlobeTrotter GT Fusion — CardBus
Option GlobeTrotter GT Max — CardBus
Option GlobeTrotter HSDPA — USB
Option iCON 225 — USB
Option iCON 505 — USB
Option GlobeTrotter HSUPA 380E — PCI Express Mini Card
Quectel EC25 — PCI Express Mini Card
Quectel EM060K — M.2
Sierra Wireless MC8755 — PCI Express Mini Card
Sierra Wireless MC8775 — PCI Express Mini Card
Sierra Wireless MC8790 — PCI Express Mini Card
Sierra Wireless AirCard 580 — CardBus
Sierra Wireless AirCard 875 — CardBus
Sierra Wireless AirCard 881 — CardBus
Sierra Wireless AirCard 881U — USB
Sierra Wireless Inc. USB 305 — USB
Simcom SIM7600E — PCI Express Mini Card
Softbank C01SW (Sierra OEM) — USB
Toshiba 3G HSDPA MiniCard — PCI Express Mini Card
Vodafone Mobile Connect 3G — CardBus
Vodafone Mobile Broadband K3765 — USB
Vodafone Mobile Broadband K3772 — USB
ZTE AC2746 — USB
ZTE MF112 — USB
ZTE MF190 — USB
ZTE MF633 — USB
ZTE MF637 — USB

devices suspected of being compatible (aka "we think so but we're not putting it on the record", 🙈):

Dell W5500 — PCI Express Mini Card
Huawei E270+ — USB
Huawei E1690 — USB
Huawei E1762 — USB
Novatel Wireless ExpressCard — ExpressCard
Novatel Wireless Merlin V620 — CardBus
Novatel Wireless Merlin V740 — CardBus
Novatel Wireless Merlin X950D — ExpressCard
Novatel Wireless MC950D — USB
Novatel Wireless S720 — CardBus
Novatel Wireless U720 — USB
Novatel Wireless U740 — CardBus
Novatel Wireless U870 — CardBus
Novatel Wireless V720 — CardBus
Novatel Wireless X950D — ExpressCard
Novatel Wireless XU870 HSDPA — ExpressCard
Sierra Wireless AirCard 595 — CardBus
Sierra Wireless AirCard 597E — CardBus
Sierra Wireless AirCard 880 — CardBus
Sierra Wireless AirCard 880E — ExpressCard
Sierra Wireless AirCard 880U — USB
Sierra Wireless AirCard 881E — ExpressCard
Sierra Wireless AirCard 885U — USB
Sierra Wireless C597 — USB
Sierra Wireless EM5625 — USB
Sierra Wireless MC5720 — PCI Express Mini Card
Sierra Wireless MC5725 — PCI Express Mini Card
Sierra Wireless MC8765 — PCI Express Mini Card
Sierra Wireless MC8780 — PCI Express Mini Card
Sierra Wireless MC8781 — PCI Express Mini Card

🎀 the whole "which port though" situation 🎀

some modems have multiple serial ports, however almost all modems have only one effective serial port for PPP connections. like, the rest are decorative. main character energy but make it one port.

the Huawei E220 has two serial ports, but only the first port can be used to make connections; the second one is for management. literally the second port is HR.
the Option GlobeTrotter HSDPA/HSUPA modems have three serial ports, but only the last port can be used to make PPP connections.
the Medion Mobile S4222 has four serial ports, but only the first port can be used to make connections.

some modems require multi-link PPP operation. for example, the Huawei E1550 has four serial ports. when initiating a connection, the control commands have to be issued on the third port, and after that the actual PPP connection comes up on the first port. the function of the second and fourth ports is unknown — they're giving mystery, they're giving side quest, nobody knows what they do 💀

🌈 EXAMPLES 🌈

an example demand dial configuration for Cingular Wireless using pppd(8) — copy it exactly, bestie, every character is load-bearing:

/etc/ppp/cingular-chat:

TIMEOUT 10
REPORT CONNECT
ABORT BUSY
ABORT 'NO CARRIER'
ABORT ERROR
'' ATZ OK AT&F OK
AT+CGDCONT=1,"IP","isp.cingular" OK
ATD*99***1# CONNECT

/etc/ppp/peers/ac875:

cuaU0
115200
debug
noauth
nocrtscts
:10.254.254.1
ipcp-accept-remote
defaultroute
user isp@cingulargprs.com
demand
active-filter 'not udp port 123'
persist
idle 600
connect "/usr/sbin/chat -v -f /etc/ppp/cingular-chat"

/etc/ppp/chap-secrets:

# Secrets for authentication using CHAP
# client                server  secret          IP addresses
isp@cingulargprs.com    *       CINGULAR1

pppd(8) is then started using:

# pppd call ac875

and that's the whole ritual. light a candle. it'll either connect or it won't. 🕯️

🔥 SEE ALSO 🔥

ucom(4), uhub(4), usb(4), pppd(8)

go read those too, i'm not doing all the work for you 💜

👑 HISTORY 👑

the umsm device driver first appeared in OpenBSD 4.0. vintage. antique. iconic.

🫶 AUTHORS 🫶

the umsm driver was written by Jonathan Gray <jsg@openbsd.org> and Yojiro UO <yuo@nui.org>. absolute legends, both of them, no notes.

💀 CAVEATS 💀

For Verizon Wireless (and possibly other services), cards require a one-time activation before they will work; umsm does not currently support this. so like. it will not work. that's the whole caveat. 😭

The additional IEEE 802.11 wireless chipset found in the Option GlobeTrotter GT FUSION is not yet supported. yes there's an extra wifi chipset in there. no, umsm won't talk to it. it's not invited to the party.

and that's the page!! 💖 this one's from the Debian build, dated May 23, 2024 — so if you're reading it some other time, that's on the manpage, not on me. mwah 🧚✨

📦 where this page comes from

nixpkgs unstable: cvs-export
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on 2026-11-04: a language model's rewrite of the original, under its terms