Resolution:
The RTserver which is generating this message has established the underlying socket connection but the peer-peer (TipcConn) level handshake is failing because the connection handshake timeout is expiring before the process which is attempting to connect responds. (The timeout here is the socket_connect_timeout). This can be due to a heavily loaded network, or a problem with the process that is trying to connect. You can try increasing the allowable timeout by using an undocumented option _Conn_Init_Timeout in the rtserver.cm file. The default value for this option is 30 seconds...  try setting it to 45 seconds and see if that resolves the problem.