Sets all reverse connections to a one connection at a time mode. Server-side applications will get a (socket) connection refused until: All data from previous connections on that serial port has drained, There are no other connections, Up to a 1 second interconnection poll timer has expired This also enables a per-connection keepalive TCP keepalive feature. After approximately 3 minutes of network connection idle time, the connection will send a gratuitous ACK to the network peer, thus either ensuring the connection stays active OR causing a dropped connection condition to be recognized by the reverse service (all connections).