Connection to 3G using PPP (RL-TCPNet)

Hello
I'm using STM32F407 with RL-TCPNet. My taks is connect 3G modem ( Telit, UL-865) to my device.
RL stack is working fine when PC connect to my device using PPP connection ( PC-Client, device-Server)

Now, i tried connect 3G modem to my device. After command to modem "ATD*99***1#" modem send back "CONNECT" and start LCP packages. The RL-TCPNet stack is not response and after 5-6 tries modem is send "NO CARRIER".
Before send command "ATD*99***1#" i'm setting the stack using next lines
ppp_listen ("Keil","");
SendToPPPStack ("CLIENT");
When i'm listening the UART communication i can see answer from stack "CLIENTSERVER".

I found that i need to establish PPP connection first before open TCP sockets. Could it be reason for the troubles with connections?
Have somebody an example to work with 3G modem using PPP connection?

Regards,
Sergiy