This object sets the alarm severity, major or minor, raised when a statistical threshold is exceeded on the SONET line layer, with the MIB noting that a threshold crossing alarm does not raise any alarm by default. An administrator must explicitly set this to major or minor to get a visible alert when line-layer error thresholds, such as errored seconds or unavailable seconds, are exceeded. For example, an administrator who wants to be paged whenever line-layer errors spike would configure this object to major rather than leaving it at the default of none.