[CentOS] External Dial-up Modem

[Bill Campbell]

On Mon, Sep 26, 2011, Graham Johnston wrote:
>I am having an issue with Centos 6 and an external USRobotics modem.  We
>use the modem as part of a last resort SMS paging system.
>
>Across multiple Dell servers, different models, I can't not get the
>modem to respond to simple AT commands while using Minicom.  At the same
>time if I connect the server to a console port on a switch I can
>successfully access the switches serial console.  So I know the serial
>port itself is working.  The modem still works fine if connected to a
>Centos 5 server.
>
>Any thoughts?

Which device are you using for the serial connection.  It should be
/dev/ttyS0 or similar to provide the correct modem control signals.  The
modem probably won't respond unless the DTR (Data Terminal Ready) line is
up.  It's been quite a while since I had to look at the modems on our
system that runs HylaFAX and dialup connections,

Bill
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