VMS Help Sys Parameters, PASTDGBUF  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The number of datagram receive buffers to queue initially for the
    cluster port driver's configuration poller. The initial value is
    expanded during system operation, if needed.

    Memory Channel devices ignore this parameter.

    PASTDGBUF is an AUTOGEN parameter.