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

    Default: 60                Value: 1-300

    Maximum time, in seconds, that can pass before an outgoing call
    is connected. This characteristic is supported only when the
    characteristic connection type is switched.