Problem: The timeout value for a lost connection is too long. Can I configure it? Solution: On Windows NT there are three TCP configuration parameters that are of interest to managing an active connection in Interbase: KeepAliveTime - The parameter controls how often TCP attempts to verify that an idle connection is still intact by sending a keep alive packet. If the remote system is still reachable and functioning, it will acknowledge the keep alive transmission. Keep alive packets are not sent by default. This feature may be enabled on a connection by an application. Value Type: REG_DWORD - Time in milliseconds Valid Range: 1 - 0xFFFFFFFF Default: 7,200,000 (two hours) KeepAliveInterval - This parameter determines the interval separating keep alive retransmissions until a response is received Once a response is receive, the delay until the next keep alive transmission is again controlled by the value of KeepAliveTime. The connection will be aborted after the number of retransmissions specified by TcpMaxDataRetransmissions have gone unanswered. Value Type: REG_DWORD - Time in milliseconds Valid Range: 1 - 0xFFFFFFFF Default: 1000 (one second) TcpMaxDataRetransmissions - This parameter controls the number of times TCP will retransmit an individual data segment (non connect segment) before aborting the connection. The retransmission timeout is doubled with each successive retransmission on a connection. It is reset when responses resume. The base timeout value is dynamically determined by the measured round-trip time on the connection. Value Type: REG_DWORD - Number Valid Range: 0 - 0xFFFFFFFF Default: 5 These parameters are found in the Registry in the following location: HKEY_LOCAL_MACHINE SYSTEM CurrentControlSet Services Tcpip Parameters To configure these and other available TCP parameters see the document titled Q120642 on the searchable knowledgebase at www.microsoft.com, or navigate to the following location using a browser: http://support.microsoft.com/support/kb/articles/q120/6/42.asp
Last Modified: 26-OCT-00