Library /sys$common/syshlp/nclhelp.hlb set, llc2, sap, link, holdback_timer  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Default: 500           Value: 0-60000

    Specifies the delay, in milliseconds, before an acknowledgment
    must be sent. The granularity of this timer is 10 milliseconds.
    Values that are not multiples of 10 are rounded down.