why can this wireless modem only dial out ?

[IPOz]

hi sir,
the following is test environment:

(windows)---(modem A)~~~~~~(modem B)---(linux)
where, modem A and modem B are different band.And modemB's phone# is 138xxxyyyzz

On linux, we can dial windows successfully using minicom.However we can NOT dial linux from windows as below:
On linux,run the following commands :
#/sbin/mgetty -D -s 9600 -m '"" ATE0S0=2 OK' -x 5 ttyS1

then on windows,start 'hyper termina' and run the following commands:

ate1
atd138xxxyyyzz

After a while, it will show:

connect/9600 ...
+++
No CARRIER

Maybe we have not initialize modemB rightly. If using a same type modem as modemA to replace modemB,it works fine !!! mgetty will receive a RING signal from modem.So we guess the modemB has not sent RING to mgetty ?
but why not ?

any suggestion ?

ipo_z@cmmail.com
garbage in,garbage out

 

[IPOz]

Moreover if adding ';'(voice) after atd138xxxyyyzz
,then mgetty can get RING but useless for digital communication, right ?



ipo_z@cmmail.com
garbage in,garbage out