Session Establishment

Session establishment differs between TCP and UDT; these differences affect how you set up firewall rules and configure the firewall navigation initialization parameters in IBM® Connect:Direct®.

TCP Session Establishment

An IBM Connect:Direct TCP client contacts an IBM Connect:Direct TCP server on its listening port. The IBM Connect:Direct client scans the list of ports (specified using the tcp.src.ports initialization parameter) and looks for a port to bind to. The number of times IBM Connect:Direct scans the list is specified using the tcp.src.ports.list.iterations initialization parameter. If IBM Connect:Direct finds an available port, communication with the remote node proceeds.

UDT Session Establishment

When an IBM Connect:Direct UDT client contacts an IBM Connect:Direct UDT server on its listening port to request a session, the UDT server responds with a different server port to use for the session. The client attempts to contact the server on the session port. The IBM Connect:Direct client scans the list of ports (specified in the udp.src.ports initialization parameter) and looks for an available port to bind to. The number of times IBM Connect:Direct scans the list is specified using the udp.src.ports.list.iterations initialization parameter. If the IBM Connect:Direct client finds an available port, communication with the remote IBM Connect:Direct server proceeds. If a session cannot be established after a certain time interval, the server attempts to contact the client.