Incoming CSD call while socket connected


I know there have been various posts on this over the last couple of years, but I wanted to get a definitive answer.

M system is using a Q64, and it makes a TCP socket connection across GPRS to a server. While this connection is made, I would also like it to be able to receive an incoming CSD call. When this happens I would like the following steps to happen;

  1. Leave socket connected
  2. Answer incoming call
  3. Receive data over CSD connection
  4. Send data over CSD connection
  5. Hang up CSD connection
  6. Switch back to socket connection using AT*E2IPATO

This works with the exception of steps 3 and 4 - that is, it doesn’t receive data and it can’t send data (which I know I am sending to it through HyperTerminal on another PC).

I could do this with a GR64, and feel that I am frustratingly close to achieving this with the Q64.

Any help gratefully received.



That’s probably because WIP uses FCM; so keeping the socket open means that WIP keeps hold of the “Flow” - and, therefore, it can’t be used by the CSD data… :question:

Right, I see. Thank you.

Is that also true if I’m using the AT commands with the GR plug in?


I don’t know - but I would guess so.

If you want an official answer to this, you’re going to have to ask your Distributor or FAE

Surely the socket would become disconnected, as the GPRS context would be lost. Or do you have a Class A device that allows concurrent GSM call and GPRS data? … io_Service