TCP Sockets and ACK / FIN detection

Hi All,
Fairly new to the Digi Connect ME device and I am familiarising myself with the device and OS API’s before developing the application we need using NET+OS.

It’s all looking fairly good with the Socket handling and sending/receiving data via mapped ports. The main problem I am coming across and cannot find a way of detecting is if the client decides to terminate/disconnect then I have no idea that the port is no longer connected. This has an effect of me not being able to kill the thread or go back to a listen state.

I thought it was the fact that the FIN command wasn’t being received by the Digi but looking with ethereal I see that when I send the disconnect FIN, ACK the Digi returns with an ACK so it has acknowledged that the command has been received.

There must be some way to do it but I have been trawling through the documentation and found nothing.

Any help is greatly appreciated and I’m sure the responses will help others.

Thanks in advance