A problem with the pppd

[a]

Help me, please, with the pppd. The problem is the next. 
I want to connect to Internet Service Provide (ISP) with a callback. 
I use the pppd and the chat with the next scripts, which are inessential
now: 

# pppd script 
 
/dev/cuad1 115200 

debug 
defaultroute 
crtscts 
noipdefault 
connect	"/usr/bin/chat -v -f
/etc/ppp/peers/login.chat.script.prostointernet.callback" 
callback 4504257 
passive 
domain	prostointer.net 
persist 
holdoff	300 

# chat script login.chat.script.prostointernet.callback 
# It is one line really

ABORT BUSY	ABORT 'NO CARRIER'  
"" AT 
OK ATS0=1 
OK ATDP5945050 
TIMEOUT 300 CONNECT "" 
TIMEOUT 30 sername:-\\r-sername: login 
TIMEOUT 30 sword: password 
"hostname:" 0.0.0.0 

The first step goes well: my side connects with the ISP and
authentication is done successfully. 
After authentication and querying a callback, pppd hangs up the line. 
But then pppd exits. 
The ISP calls me back after some time. But there is no pppd already, and
nobody is waiting for the incoming call. 
(Without callback I have no problem.) 

What do I wrong?

mailto:a at zeos.net