There is no tone on an outgoing call

Hello, everyone.
I’m having a strange problem with my asterisk. After dialing and before the other side picks up the phone I should hear the tones (I’m not sure what are they called: piiiiiiiiiiii—piiiiiiiiiiiiii…) and in almost all cases that is true. However there is a range of numbers where I’m having this problem. There is no tones, just silence, until someone picks up the phone. This does not occur when I call to those numbers with a mobile or regular PSTN phone.
Has anyone experienced anything similar? Where I should be looking to correct this?
Thanks in advance

P.S. I’m using asterisk 1.2.18. The Dial command is the same for all calls: _X.,n,Dial(SIP/${EXTEN}@provider-out,45)

Today I was speaking with my telephony provider. They said that they are sending to my asterisk a 183 message and that should be enough to hear the “ring-back” tone. Do I have to change something in the configs to have this option interpreted?

hi facha,

although it does not fix your problem, a workaround is to add ‘r’ to your dial command options. This will give you an asterisk generated ringing tone while you wait for other party to answer.

seabro

Thanks for your reply. I had it configured that way for a short while… This way asterisk will still give you a ringback when the other side is not available. The clients were complaining and finally I’ve removed the “r”.