i am trying to use modem to dial phone,i am able to do it but after some time i get tones like dtmf tones on the receiver phone,i am using javax.comm package for serial communication,i think some additional AT commands other than "ATA " is to be used but could not find.
someone can guide me to the correct way to do so.
it will really be a great help.
thanks in anticipation

Here are the most common AT commands
I used javax.comm many years ago, and found it to be not very good quality.
Alternatively, under Windows, you can use TAPI (via Com4j or Jacob java/COM bridges), which is a far more modern approach, but a bit tricky and a big learning curve. I have some working code that could help if you chose to go this way.

thanks for your reply,
actually i want to know that sending "ATA" command to modem is sufficient to make a call?? as the incoming call is received using this command.
in my case the connection is established using this command but after few seconds the undesired sounds starts,the connection is established but with above fault,so i want to know what should be done to get rid of this problem.thanks

The modem can be used to automatically dial voice calls when a telephone is connected to it. Placing a semi-colon at the end of a dial string forces the modem to return to on-line command mode after completing the dial string. The modem does not attempt to establish a data connection. The progress of the call can be monitored via the modem's speaker. If the call is answered, pick up the telephone handset and issue the ATH0 command (or lower DTR) to put the modem on hook. You may now proceed with a normal voice call.

If you are trying to answer a voice call on your modem, then what exactly do you want the modem to do with it?

thanks.i will try the ; method i have a voice modem and i am trying to make a phone tool,to receive and make calls.so for making a call,i used the "ATD phone number\r\n" command which makes the call correctly,
for receiving i am facing problems:-
1.by sending "ATA \r\n" command the incoming call is received but after few seconds the tones are heard in the dialing phone line,
i used the "ATM2 \r\n" command to set the speaker status the same tones are heare in the speaker.
i cannot figure out the reasons for this problem.
please help to figure out the problem

my final aim is to use the mic and headphone ports of the modem to answer and make voice calls, hope i am clear with my objective.
thanks for your concern

ATA will try to answer the phone in modem mode and negotiate a data connection - that's why you are hearing the tones. You need to answer the call in voice mode.
I've never had to do that, so I have no personal experience of it, but in theory you can set the modem into voice mode with the command #CLS=8 (probably with at AT in front?) then when you issue the ATA the modem will already be in voice mode and will not attempt to negotiate a data connection.

this theory did not worked. conceptually it is correct but not working...
i also tried AT#VLS=1 which is to answer the call in voice mode,the connection is established but with the same fault.I think doing so made it clear that problem is not due to the voice mode but something else.
your experience is really helping in other cases too,if u have some other idea please inform,the idea could even be any of the hit and trial method any idea regarding the same,i would really appreciate, thanks.

i use a regular phone i.e a land line number to dial the number of the line which i pulgued in the modem to receive.

i use a regular phone i.e a land line number to dial the number of the line i have pluged in the modem

i use a land line number to dial the number of the line connected to the modem

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