PPP connection timeout

Myabe somebody helps me…

I have ppp connection via modems and 4w leased line.
Sometimes modems break line and pppd founds it in 20 - 30 sec or even more.
How can I setup this timeout?
And the second.
I have shell script that controls pppd. As described in manual, pppd creates
file in /etc/ppp when ppp works.
Script checks this file every 2 sec and when it cannot find this file it
runs pppd again.
Sometimes I found that more then 20-30 pppd working (or waiting something)
in system.
What’s happening?

Thanks in advance,