Understanding extensions.conf line

I am fairly new to using asterisk and am trying to understand the meaning of 2 variables in a string:

exten => _X.,1,Dial(IAX2/FaxIAX0/${EXTEN},30,r)

I understand
_X will allow any digit from 0-9,
1 makes this a priority
Dial(IAX2/FaxIAX0/${EXTEN} - Dials that location - to my knowledge and understanding.

I am curious what the (30, r) represents, if anyone could help explain this, i cant seem to find it anywhere in documentation. Thank you

voip-info.org/wiki/view/Asterisk+cmd+Dial .


Marco Bruni

thank you so much. your a life saver.