ESA Server

The ESA Server object controls the Emergency Standalone function for a MG3510 or MG2510 Media Gateway and optionally one or more third-party MGCP media gateways or MGCP Subscriber Gateways. The group of gateways that it protects is called an ESA Protection Domain.

There is one ESA Server object as a child of the MetaSwitch object for each MG3510 or MG2510 Media Gateway in your installation. This object is pre-configured (configuration information is delivered with the NE), and you cannot create or delete it.

For more details about Emergency Standalone function, refer to the Emergency Standalone Guide.


If you deactivate an ESA Server while it is in controlling mode, the Media Gateway will be restarted, forcing termination of all active calls. Control of the ESA Protection Domain will pass back to the Call Agent; if the Media Gateway cannot establish connectivity with the Call Agent, none of the gateways in the domain will be able to provide service. If you deactivate an ESA Server while it is in standby mode, it will no longer be able to provide any protection to the ESA Protection Domain in case of a Call Agent connection failure. In either case, the ESA Protection Domain associated with this ESA Server will not function while the ESA Server is deactivated. You may prefer to deactivate the ESA Protection Domain at the same time.


Parameter

Access

Description
Server name Change A unique name for this ESA Server in the EMS display. For clarity, you are recommended to give the ESA Server the same name as the ESA Protection Domain that references it.
Call Agent IP address Read only IP address of the Call Agent to which this ESA Server corresponds.
ESA control status Read only This field appears only if Actual status is Active. Specifies whether the ESA Server is controlling the ESA Protection Domain. Values:
  • Standby
    The ESA Server is not controlling the ESA Protection Domain, but is on standby ready to take over control from the Call Agent if there is a problem.
  • Controlling
    The ESA Server is controlling the ESA Protection Domain.
Number of emergency calls in progress Read only This field appears only if ESA control status is visible and set to Controlling. The number of emergency calls currently in progress on the ESA Protection Domain. Automatic switchback will never occur while there are any emergency calls in progress. If necessary, you can force a manual switchback while there are one or more emergency calls in progress, but these calls (along with all other calls) will be terminated on switchback.
Call Agent connection status Read only This field appears only if Actual status is Active. The ESA Server's view of its connection to the Call Agent. Values:
  • Up
    The connection is operating normally.
  • Down
    The ESA Server has been unable to receive valid messages from the Call Agent for 25 seconds, and so considers the connection to be down.
Call Agent status Read only This field appears only if Actual status is Active. The status of the Call Agent, as indicated in its last valid message to the ESA Server. Values:
  • Not participating
    The Call Agent is not controlling the ESA Protection Domain.
  • Cautiously controlling
    Either the Call Agent is controlling the ESA Protection Domain but the ESA Server can take over control if necessary, or the Call Agent is ready to resume control after switchover but switchback has not yet occurred.
  • Controlling
    The Call Agent is controlling the ESA Protection Domain.
  • Unknown
    The ESA Server cannot determine the Call Agent status (for example because the connection is down).
Time of last connection failure Read only Date and time at which Call Agent connection status last changed to Down.
Time of last config synchronization Read only Date and time at which the ESA Server last received configuration information from the Call Agent. Config synchronization is specified in the ESA Protection Domain object below the Call Agent. It normally occurs at regular intervals, or you can force an immediate update (for example if you have just made major configuration changes and do not want to wait until the next scheduled update).
Switchover - suppress automatic switchover Change Specifies whether switchover from the Call Agent to the ESA Server must be activated manually or can occur automatically. Values:
  • True
    Switchover must be activated manually, as described in the Emergency Standalone Guide.
  • False
    The ESA Server will take over control from the Call Agent if its connection to the Call Agent is down for the period specified in Switchover - automatic switchover qualification time.
Switchover - automatic switchover qualification time Change This field appears only if Switchover - suppress automatic switchover is False. Time in minutes for which the Call Agent connection must be down before automatic switchover occurs. The default is 5 minutes.
Switchover - time of last switchover Read only Date and time at which the ESA Server last took over control of the ESA Protection Domain.
Switchover - reason for last switchover Read only Reason for the last switchover from the Call Agent to the ESA Server. Values:
  • Has not occurred
  • Automatic
  • Requested by Call Agent
  • Forced through craft scripts
Switchback - expected round trip time Change Expected round trip time in milliseconds for messages from the ESA Server to the Call Agent. This value is used (together with the following two fields) to assess the quality of the Call Agent connection when it is restored after a switchover, to determine whether it is appropriate to switch back. Range: 0 - 10000 ms (0 - 10 seconds). The default is 500 ms (0.5 second).
Switchback - qualification period Change Time period in seconds over which the Call Agent connection quality is monitored when it is restored after a switchover, to determine whether it is appropriate to switch back. Range: 0 - 600 seconds (0 - 10 minutes). The default is 180 seconds (3 minutes).
Switchback - message acknowledgement threshold Change Threshold for measuring the quality of the Call Agent connection when it is restored after a switchover, to determine whether it is appropriate to switch back. This field specifies the percentage of messages from the ESA Server to the Call Agent, over the period specified by Switchback - qualification period, that must arrive within three times the value of Switchback - expected round trip time for the connection to be considered good enough for switchback. The default is 95%.
Switchback - current message acknowledgement rate Read only Percentage of messages from the ESA Server to the Call Agent, over the period specified by Switchback - qualification period, that are currently arriving within three times the expected round trip time. When this value equals or exceeds the value in the previous field, the connection is considered good enough for switchback. Each message's round trip time is compared with the expected time value that is configured when it is sent and received. If you change the expected time during the qualification period, it does not affect whether earlier messages are considered to have qualified.
Switchback - time of last switchback Read only Date and time at which ESA control status last changed to Standby, returning control of the ESA Protection Domain to the Call Agent.
Alarm state Read only The alarm state of the ESA Server. Values:
  • Clear
    The object does not currently require maintenance action.
  • Attention Required
    The object requires maintenance action.
Alarm log correlator Read only Identifier of the log message for the event that caused the last Attention Required alarm state for this object. This field is reset when the Attention Required alarm events field is reset to zero.
Attention Required alarm events Read only / Reset Number of times (since this field was reset) that this object's alarm state has gone to Attention Required.
Alarm state changed timestamp Read only Time at which Alarm state last changed.
Alarm events reset timestamp Read only Time at which the Attention Required alarm events field was last reset to zero.
Diagnostics - API trace - enabled Change Specifies whether API tracing is enabled for this object. Values:
  • True
  • False (default)
Diagnostics - API trace - trace tag Change An optional text string inserted into API tracing and PD logging for this object. (This string can include accented / international characters as defined in ISO 8859-1.) If you want to filter on this tag in the craft interface, do not include spaces or any of the characters ^ \ $ * + ? | ( ) , . ' ' " [ ] { }.
Requested status Read only Specifies whether an administrator has attempted to activate the ESA Server. Values:
  • Active
    The object has been activated.
  • Inactive
    The object has not been activated or has been deactivated.
  • Disabled
    The object has been disabled.
Actual status Read only Specifies the current status of the ESA Server. Values:
  • Active
    The object is active.
  • Activating
    Activation is in progress.
  • Deactivating
    Deactivation is in progress.
  • Inactive
    The object is inactive.
  • Disabled
    The object has been disabled.
  • Activation Failed
    The object is inactive because an activation attempt has failed.
  • Failed
    The object was active but has failed.
  • Quiescing
    The object is preparing for normal deactivation.
  • Waiting For Parent
    The object cannot be used because its parent object is not yet active.
  • Parent Failed
    The object cannot be used because its parent object has failed.