SNAX/HLS Configuration and Control Manual

Step 3. Planning Session BINDs
Planning the SNAX/HLS Environment
2–10 104705 Tandem Computers Incorporated
Common FM Usage BIND bytes 6 and 7 determine attributes that apply to the session as a whole.
Session Segmenting Support.
This attribute determines whether segmentation can occur for the session.
Segmentation refers to the division of chain elements into smaller packets for
transmission. This attribute is not interpreted by SNAX/HLS.
In the BIND message, this attribute is indicated in byte 6, bit 0. In HLSRDT, this
attribute is specified by the BIND attribute NO-SEGMENTS, where: NO corresponds
to 0 in the BIND message and YES corresponds to 1 in the BIND message.
FM Header Usage
This attribute determines whether function management headers (FMHs) will be
used. Consult the product or component description guide on the requirements for
FMH support.
Be aware that some IBM products (for example, CICS) expect programmable
controllers like the 3600 to send and receive FMHs.
In the BIND message, this attribute is indicated in byte 6, bit 1. In HLSRDT, this
attribute is specified by the BIND attribute FM-HEADER-USE, where: NO
corresponds to 0 in the BIND message and YES corresponds to 1 in the BIND message.
Brackets Reset and Usage State
SNA brackets are used to demarcate logical units of work. They can be used only in
half-duplex send/receive modes. They might be required if certain recovery features
are required from the IBM devices or by the protocol. Set this field after consulting the
appropriate device or product guide. The typical setting for a 3270 LU session type 2
is 1 (that is, brackets are used and the reset state is BETB (between brackets)).
In the BIND message, this attribute is indicated in byte 6, bit 2. In HLSRDT, this
attribute is specified by the BIND attribute BRKT-RESET, where: INB corresponds to 0
in the BIND message and BETB corresponds to 1 in the BIND message.
Bracket Termination Rule Selection
This field selects the bracket termination rule. Set this field in accordance with the
application design and the requirements of the product or device.
In the BIND message, this attribute is indicated in byte 6, bit 3. In HLSRDT, this
attribute is specified by the BIND attribute BRKT-TERM, where: UNCONDITIONAL
corresponds to 0 in the BIND message and CONDITIONAL corresponds to 1 in the
BIND message.