ECHO problem


I’ve developed a multithread CIFS server which runs
on NT box. I am using
NetBIOS API for communication with clients. And I’ve
got a problem in the
following scenario:

  1. Client sends write request to CIFS server.
  2. CIFS server gets the request and puts it in a queue for
  3. CIFS server enters receive procedure again (NetBIOS
  4. Job thread starts request processing and does not answer
    for a long time ~30 minutes
  5. After that client’s behavior is different.
    Some clients send ECHO request (CIFS server immediately
    answers) and after that
    clients are patiently waiting, other clients just reset
    connection after a timeout.

I wonder if there is a way to force client to send ECHO
instead of connection

For my server it is legal to process a request for a very
long time (30 minutes
or even more). SESSTIMEOUT is not good solution,
because every client has to
change the registry.

Any ideas would be greatly appreciated.