Operator Interface

Xenon operator interface is implemented using SNMP (Simple Network Management Protocol). Interactions between the operator and the system can be broadly classified into the following categories:


Operator uses commands to configure and change the system configuration. The system executes the operator command and responds back with a report. Examples of a few Xenon commands are:

  • Create a V5.2 interface
  • Change the state of a XEN card to Under-Maintenance.
  • Run periodic diagnostics on the system
  • Create a V5.2 Subscriber
  • Obtain current system statistics

Alarms are generated when an abnormal condition is detected by the system and might need operator intervention to alleviate the problem. The alarms are classified as critical, major and minor to signify the urgency of the alarm. The alarms are cleared when the system reaches a normal state. A few examples are:

  • A critical alarm is raised if a XEN card fails
  • A major alarm is generated if a digital trunk failure is detected.
  • A minor alarm is raised when high digital trunk error rate is detected.
  • A critical alarm is generated when the CPU utilization on the XEN card exceeds 70%.

Events are generated to notify the operator of routine occurrences in the system. Unlike alarms, events do not need to be cleared. A few events generated by Xenon are:

  • Billing information for the week has been sent to the billing system.
  • Routine diagnostics have been completed
  • Subscriber line has entered line lockout state due to the subscriber leaving the phone offhook.
  • A call record is generated for a call, giving complete information about the duration, calling and called phone numbers

Operator Interface Architecture

As mentioned earlier, the operator interface is implemented using SNMP. The OMC runs the SNMP manager which manages all the objects in the system. These objects are referred to as managed objects. Basically every entity in the system is considered to be a managed object. A few examples are, a XEN card, V5.2 subscriber, a digital trunk.

Operator commands about managed objects are sent by the OMC in a MIB (Management Information Base). The MIB is received by the SNMP agents running on CAS and XEN cards.

SNMP Operations

The commands, alarms and events are implemented in terms of the the following SNMP primitives:

  • SNMP Get: This command allows the SNMP Manager running on the OMC to obtain information from the SNMP agents running on XEN and CAS. SNMP Get is used to implement statistics and query commands.

  • SNMP Set: This command allows the SNMP Manger to set values for the managed object. SNMP Set is used to implement creation and modification commands.

  • SNMP Trap: This command is used by the SNMP Agent to notify the SNMP manager about various events. SNMP trap is used to implement alarms and events.