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).
- Send/Receive Mode Protocol - The connector supports
half-duplex flip-flop mode.
- 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.