Using an external modem

Hi all,

I wrote an application where a Q2686 module is collecting data from sensors which are later send to an FTP server via GPRS using the WIP libraries. The application is working very reliable now for more than a year. Now I would like to use the same application with small modifications in an environment where no GSM/GPRS network is available.
Therefore I will use an external satellite modem (e.g. Thuraya network) as transparent interface to transmit the data to the FTP server. After reading the WIP documentation it seems that there is no other option than using PPP over UART as bearer.
To start testing I made a setup in my office where a Q2686 modem (A) is running with a small OpenAT application that tries to open a PPP over UART2 bearer using the WIP library funtions. UART2 of modem A is connected to UART1 of another Q2686 (B). Modem B will act as the transparent interface (instead of Thuraya currently German T-Mobile) and hopefully will dial up and establish PPP.
Within a couple of days of testing I did not get the setup to work (neither with thuraya nor t-mobile) and I came to the conclusion that it is not possible to implement the above mechanism by using only the WIP library funtions.

My question is: Does anybody of you developped a similiar application and could give me a hint how this was solved?

Best regards,
Christian