I use Fastract Supreme 20 modem with R71b firmware on it.
Sometimes my wip_TCPServerCreate function returns NULL. It is rare but annoying. The documantation says it means an error occurs when trying to create server socket. But how can i get the more information about the error? How can i get to know what causes this error?
The bearer status is “WIP_BEV_IP_CONNECTED” which means gprs connection is established. What is more, before the corresponding wip_TCPServerCreate function, i can successfully open a TCP client socket to send data to a server from modem. But after this client connection, it can not open a server socket (sometimes).
Connect to gprs
Create a TCP Client socket and send data to a server
Close the client socket
Create a TCP Server socket to listen a port.
It sometimes fails on 4th step. Note that it happens on the firmware of R71b. I didnt see any failure on firmware 663 series.