Why ring tone be heared before the destination phone ring

I setup two asterisk server connected through ip network. One server used for iax phone registering, one for connecting to PSTN(use PRI).
When my iax phone dial number ended by #, i can here ring tone immediately before the destination number beging to ring.

sounds like one of your Dial() statements uses the ‘r’ flag…

also paste appropriate extensions.conf segments…

I would think that being strictly VOIP and on the same LAN segment you might expect synchronized ringing. But if it’s anything like the PSTN you will almost always here the phone in your ear ringing while the phone you’re calling is silent…and visa-versa.

Remember a ring tone is not the actual dialed phone ringing…it’s only the systems way of reassuring a human that something is happening.

The problem is when the called phone is busy,but the calling phone still here ringtone not busy tone. How to make the calling phone be silence untill the called phone ringing and when the called phone is busy, the calling phone can hear busy tone?

[quote=“IronHelix”]sounds like one of your Dial() statements uses the ‘r’ flag…

also paste appropriate extensions.conf segments…[/quote]

did you read this ?