Cisco Network Clock Manual Source Entry

1.3.6.1.4.1.9.9.121.1.2.1.1

Network clock status and statistics for sources of network clock. When the value of cncDistributionMethod is 'manual', the managed system uses this table to select a source of network clock for the managed system. Within this table a physical entity that is a source of network clock is identified by cncManualSourceId. Table entries are indexed by priority (cncManualSourcePriority). A source of network clock for the device may be an oscillator local to the device, a Building Integrated Timing Supply (BITS) port or an interface that supports synchronous clock recovery. (BITS is explained in more detail in Bell Communications Research, GR-436-CORE, 'Digital Network Synchronization Plan'.) When the managed system initializes it creates a row for the device's default source of network clock, (the entry having cncManualSourcePriority with value 'default'). The only operations allowed on the columnar objects in this particular row are read operations. Other rows are created or destroyed by a management station or through the device's local management interface when a source of network clock is configured or removed. When a management station creates a row it creates it explicitly using RowStatus with either createAndGo or createAndWait. A row is not made active until a valid value for cncManualSourceId is supplied. A management station may perform a write operation on any columnar object while the row is active or not in service. The value of any instance of cncManualSourceId located in the table is unique except when the value refers to the device's default source of network clock; any instance of cncManualSourceId within the table may have this value at any time.