Negotiable versus nonnegotiable BIND

As the primary half session, IMS sends either a negotiable or nonnegotiable BIND, depending on parameters in the VTAM® mode table.

The mode table entry is indicated on the VTAM CINIT or IMS /OPNDST commands, or defined on the TERMINAL macro during IMS system definition.

Definitions:

When sending a negotiable BIND, IMS sets the bind parameters. Because the secondary half session can change some parameters, all the parameters are checked for validity by IMS when a negotiable BIND response is received.
Prior to sending a nonnegotiable BIND, IMS checks all parameters from the mode table entry for validity. The session is terminated if IMS finds any incompatible parameters.

As the secondary half session, IMS receives both the negotiable and the nonnegotiable form of BIND. When receiving a negotiable BIND, IMS checks the bind parameters, except the secondary network addressable unit (NAU) protocol field, for validity. IMS then sets the secondary NAU protocol field for the negotiable BIND response.

When receiving a nonnegotiable BIND, IMS checks the bind parameters, except for STSN required and BIS sent, for validity prior to accepting the BIND. IMS must then operate under the secondary NAU protocol definition provided in the bind.