You can use the functions IlsTcpMvProcess::AddInput and IlsTcpMvProcess::RemoveInput to register and unregister foreign file descriptors to the MvTCP main loop. The MvTCP main loop will incorporate them in its file descriptor set that is passed to the select system call. As soon as an event is detected in this file descriptor, MvTCP invokes the callback you have registered with the extra argument you provided.