Library /sys$common/syshlp/nclhelp.hlb set, osi_transport, template, checksums  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Default: False         Value: True or false

    Specifies whether the use of checksums should be negotiated for a
    transport connection. This attribute is valid for protocol class
    4 only.

    set  [node node-id] osi transport template template-id -
         checksums boolean

    Example:

    set osi transport template default checksums false