All Busy PSTN response

Is it possible to get asterisk to just stay in a ringing state instead of the standard ?all circuits are busy. Please try your call again later?

What I ultimately want is to have a queue that tries ringing my mobile and just to keep the caller in the queue if all the PSTN lines are busy. At the moment when all the lines are busy the caller is transferred to the standard ?please try your call later? ? not very friendly to the caller