3.2.5.8 KeepAlive Request (Request and Response)
The server MUST first follow the steps specified in section 3.2.5.1.
The KeepAlive response MUST follow the rules in section 3.2.5.2 and 2.2.2.3.
If the value of the Session-State variable is STREAMING and the value of the Request-Connection variable is equal to the value of the Data-Connection variable, the server MUST continue sending $D packets and MUST send the KeepAlive response to the tail of the list in the Pending-Responses variable.
If the server does not add the KeepAlive response to the Pending-Responses variable, then the server MUST send the KeepAlive response.
If the value of the KeepAlive-Mode variable specifies that the non-pipelined mode of the protocol is used, the server SHOULD close the TCP connection after sending the KeepAlive response.
The server MAY ignore the xKeepAliveInPause (section 2.2.1.4.34) token.