TcpOption

Use the procedure shown in Figure 1 to set an option for a TCP connection.

Figure 1. TcpOption example

     procedure TcpOption
              (
              Connection: ConnectionType
              OptionName: integer
              OptionValue: integer;
         var  ReturnCode: integer;
              ); external;

Parameter

Description

Connection

The connection number, as returned by TcpOpen or TcpWaitOpen in the Connection field of the StatusInforType record.

OptionName

The code for the option.

Name: Description
OPTIONtcpKEEPALIVE: If OptionValue is nonzero, then the keep-alive mechanism is activated for connection. If OptionValue is 0, then the keep-alive mechanism is deactivated for the connection. When activated, the keep-alive mechanism periodically sends a packet on an otherwise idle connection. If the remote TCP does not respond to the packet or to retransmissions of the packet, then the connection state is changed to NONEXISTENT, with reason TIMEOUT connection.

OptionValue

The value for the option.

ReturnCode

Indicates success or failure of call.

Possible return values are:

OK
NOsuchCONNECTION
NOTyetBEGUN
TCPipSHUTDOWN
INVALIDrequest
SOFTWAREerror
REMOTEreset

For a description of Pascal return codes, see Table 1.