Modem won't connect at full speed

Don Lewis truckman at
Tue Aug 19 21:57:28 PDT 2003

On 19 Aug, Lars Eighner wrote:
> On Tue, 19 Aug 2003, Don Lewis wrote:
>> On 19 Aug, Lars Eighner wrote:
>> > This has been answered by somebody on some forum, but I lost it.
>> If you manually dial using cu or tip, what connection speed does the
>> modem report?
> Oh geez, pull out the manual and spend all night trying to figure
> out how to config cu or tip, whatever they are!

You should be able to do the same with minicom.  While on-hook, just

	ATDT your_isps_phone_number

>> >    BAUD=9600  PARITY=N  WORDLEN=8
>> >    DIAL=TONE    ON HOOK   CID=0
>> It is somewhat worrysome that your modem is reporting 9600 BAUD in the
>> fixed DTE speed setting.  I don't know about USR Internal modems, but at
>> least some implementations will pace the data flow rate to the reported
>> DTE speed to avoid overwhelming the host with quick bursts of
>> interrupts.  This might be the reason for your slow connection speeds.
> Hmmm.  Of course this is "on hook."  I obtained these values using
> minicom.  I don't know how to talk to the modem when it is connected
> to somewhere, or more to the point how to query it.  I assumed the
> 9600 here was just the default for talking to the serial port, not
> the pass-through.

Because your modem is configured with &B1, the DTE baud rate won't
change when the modem connects.  If you manually dial with ATDT, the
CONNECT response should indicate the modem to modem connection speed
because you have extended response codes enabled (X4).  If it reports a
high connection speed, then you can eliminated a poor connection and
certain modem configuration problems as the cause of the problem.

If this was a serial modem the DTE speed wouldn't change if the
connection is initiated by the host.  If your internal modem attempts to
emulate the instantaneous I/O speed of a serial modem, then the fact
that it is locked at 9600 BAUD will severely limit the potential data

It's also possible that the modem is reporting 9600 BAUD just because
that is the speed that you are connecting to it with minicom.  You
should probably check the speed stored in NVRAM with the ATI5 command.

More information about the freebsd-hackers mailing list