The SNA JCA LU0 Connector supports connection management and security management
contracts but does not provide support for transaction management. To communicate
with a secure host, the client provides the user ID and password as part of
a request message.
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.