[asterisk-users] IAX2 ring cadence / time

[Joseph]

Is the a way for IAX2 adapter to detect when the calling party hangs up the phone?
I have two IAX2 adapter, one is Digium IAXY when I call the IAXY extension and hang up the phone the IAXY adapter rings about two or three times after the 
calling party hangs up the phone.

The new adapter AG-188N with IAX2 protocol as well does the same thing, the phone rings 2 or 3 times after the calling party hangs up the phone.
Is it controlled by the asterisk or an adapter? The adapters don't have any such settings. 

SIP doesn't do that, rings cuts off as soon as the caller hangs up the phone.

-- 
Joseph