The SNA JCA LU0 Connector provides the following support for the SNA Flow Control protocols:
▪ Chaining Protocol - The connector automatically performs chaining and returns a chained message to the application if the original response message would exceed the maximum RU size. The connector also builds SNA headers from the sent information message and sends the Change Direction Indicator (CDI) along with a Last In Chain (LIC).
▪ Bracket Protocol - The connector manages the bracket protocol to inform the application of the bracket status. It also handles the CDI indicators. The connector sets the session to the between brackets state when the connector has received an End Bracket (EB) message but not yet received a new Begin Bracket (BB) message. When the session is in the between brackets state and the connector sends a chain message, the first message in the chain has the BB indicator.
▪ BID Protocol - At the session level, the connector manages the BID protocol to generate a positive response if the session is between brackets. Otherwise, the connector generates a negative response. When the session changes to the between brackets state, the connector sends a Ready To Receive (RTR) command to accept data coming from the host.
▪ Function Management Headers (FMH) Protocol - The connector removes the FMH if it received a message with an FMH and the fmhIncluded attribute was enabled. If the connector sends a message to the host with an FMH, the fmhHeaderSent attribute must be enabled.
▪ Response Protocol - The connector session handles the responses.