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

    Default for Tru64 UNIX: 30      Value: 1-65535

    Default for OpenVMS: 60         Value: 1-65535

    Time, in seconds, that NSP waits for data to be transmitted or
    received before testing a transport connection. When this timer
    expires, NSP sends a data request PDU to the remote NSP. This
    PDU does not change the flow control parameters, but does require
    acknowledgment.  For Tru64 UNIX, You can modify this
    characteristic to a lower value only when the entity is disabled.

    set [node node-id] nsp keepalive time integer

    Example:

    set nsp keepalive time 60