There are a number of major lines of 3com/US Robotics modems:
ATI7modem command. The ‘Supervisor rev’ version listed should be at least ‘6.5.3’, better ‘7.1.8’ (this is the ‘X.2 upgrade’).
Fax polling still doesn’t work, and if you send faxes to a modem that can
only accept fax with 7200 bps, it will fail with
+FHS:25 unless you
sendfax -M 7200.
The Courier series does not have voice features.
ATI7does not list ‘V34’ in the ‘Options’ line, you might try setting
modem-quirks 0x20in mgetty.config. Maybe it helps. But don’t expect too much.
Some older USR firmware versions had severe bugs when doing RTS/CTS (that is, hardware) flow control. Occasionally, a byte got lost, and sometimes this confuses the modem enough to abort transmission with the error message
Transmission error: +FHNG:44 (Unrecognized Transparent data command)
Sam Leffler recommends using Xon/Xoff flow control for both fax sending and
fax receiving (
#define FAX_SEND_FLOW FLOW_SOFT and
FAX_REC_FLOW FLOW_SOFT in policy.h).
Some day in the future, I’ll make those "quirks" configurable from the config file, but until then, you’ll have to live with recompiling. Sorry. (Upgrade your firmware!).
Fax polling with the USRs is not working, even though the modem claims so. It will work half-way through, but fail miserably later.
When sending faxes with an USR faxmodem, set
ignore-carrier yes in
sendfax.config. Otherwise it will fail after the first page with a
read error and error code -5. (But that is default anyway, if you use
mgetty 1.1.16 and up).
For some fax receivers, a problem remains: the USR modems do not want
to negotiate 7200 bps transmission speed. If the receiving modem won’t
accept 9600 bps, transmission will fail after sending three DCS frames,
with the error code +FHS:25. In that case, try setting
fax-max-speed 7200 in sendfax.config.
RSPEC errors: some series of USR Sportsters and early Couriers
have bugs in the handling of the
AT+FCC command. It’s meant to specify
the maximum transmission speed, like “14400”, but these modems interpret
it as minimum speed, so they fail if sending to a machine that
can only do 9600 bps. If you see RSPEC errors in the sendfax log (+FHS:24),
try the setting
modem-quirks 0x20 in sendfax.config. This
sendfax not to set the corresponding
The USR modems support Caller ID delivery (both the I-Modem series and the
analog ones). Switch it on with
AT#CID=1 and mgetty should
automatically be able to recognize the incoming caller ID. If not, show
me a detailed log file...
Firmware upgrades and documentation are available on
in the directory /pub/USRobotics/modem/....