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

    Default: No default    Value: Local entity name

    Name of the Physical layer and line entity over which the LAPB
    protocol is to operate. You must give this characteristic a value
    before you enable the link.