IP TUN/TAP Channel Function broken?

Hi guys

I was testing the TUN/TAP Function: tun = wip_TUNCreate( gateway, 0,tunHandler,NULL);
where gateway is the address of GPRS or ethernet interface.
I get the following error from Uart: ERRLOG ch_tun.c:126: Can’t create socket

Am I doing the parameters all wrong? or is the function just broken?
I am not 100% sure what it does, so I am at the stage to tests whether it could capture a packet from GPRS, then send it to OAT, do some manipulation, then open another TUN with ethernet then send that packet of the ethernet interface.
Will it do that? Is it possible?