DIAGRAMA DE ÁRBOL VOZ DEL CLIENTE

When an automatic switchover to the redundant controller is commanded, the following sequence of events take place.

Process Steps

1 In case of failure of any crucial components causes the standby controller to compare its operational health against the health of the active controller. An automatic switchover is initiated if the standby controller is capable of wide area trunking.

2 If the standby controller is capable of wide area trunking, the standby controller informs the active controller, through the negotiation link, that it is going active and the active must go to standby.

3 All sites in the zone lose connectivity to the controller and subsequently enter local site trunking mode. If the controller has malfunctioned, the switch to local site trunking has probably already occurred.

5.11.3.1 Possible Call Processing Behavior During Recovery

7 As each site transitions to wide area trunking from local site trunking, they transmit a wide area System Status Outbound signaling Packet (OSP) to inform the radios of the change.

The time duration to transition from wide area trunking to local site trunking and return to wide area trunking varies depending on system size and configuration but should take less that two minutes.

8 If the radios ended up on a site other than their starting point during their search for a wide area trunking site, they transmit an Inbound signaling Packet (ISP).

9 The active controller begins gathering the current location of radios and talkgroup members from the affiliation tables sent from the sites.

Only limited wide area services are available until the controller receives all of the site affiliation tables. The time to recover the site affiliation information varies depending on the number of active radios, talkgroups, and the number of sites in the system, but should be less that twenty minutes.

10 For multizone systems, if the active controller is the controlling zone for an interzone call, it must also receive talkgroup affiliation information from the other zones before those zones are included in call requests. The time required varies depending on the number of radios and talkgroups in the system but in general should be less than 25 minutes. Prior to this being completed, interzone services to other zones may be affected.

11 The newly standby controller resets and if it initializes in service mode, the controller receives infrastructure,

radio, and talkgroup information from the ZDS. This includes all infrastructure, radio user, and talkgroup configuration information.

5.11.3.1 Possible Call Processing Behavior During Recovery

The table lists the types of call processing disruptions that may occur during the recovery of the primary controller. These disruptions could be caused by incomplete location and configuration data.

Table 5-5 Call Processing Behavior During Recovery

Call Type Possible Disruptions

Private Calls/Telephone Interconnect Calls

Calls to a target radios whose affiliation is not yet known to the controller are not successful.

Talkgroup/Announcement Calls Talkgroup members need to have at least one affiliated member known by the controller at their site, to be included in talkgroup calls.

5.11.3.1.1 Radio Scatter

All of the sites transition to local site trunking mode regardless of whether a controller switchover is automatic or user-initiated. The sites notify the radios of this change through a System Status Outbound signaling Packet (OSP). Upon receiving this OSP, the radios automatically start scanning the adjacent site list for another site that is still in wide area trunking mode unless the site that the radio is currently registered to is set to Always Preferred in the radio programming. When no wide area site is found, the radio stops scanning and returns the original site.

Some radios can be registered at more than one site during controller switchover. Multiple registrations can occur if a radio happens to register to a new site while the radio is also searching the adjacent site list for a wide-area site. Because connectivity to the controller is temporarily lost during controller switchover, entries in some of the site registration tables do not get updated to reflect radios who have changed sites. Normally the controller de-registers radios when they roam out of a site, however, during a controller switchover the communications path from the controller to the site is temporarily unavailable preventing the controller from performing deregistration.

The site transitions to wide area trunking mode when the site reestablishes a link with the controller. The site then notifies the radios of the change through System Status OSP.

The wide area feature called Dynamic Site Assignment requires that the controller have up-to-date affiliation tables. All sites need to upload the affiliation tables to the controller. After the controller receives all of the uploads from the sites, it looks through the compiled affiliation table for radios that are registered on more than one site. If the controller finds duplicate affiliations it requests, through all sites where the radio shows registrations, that the radio reregister. This must happen before Dynamic Site Assignment can guarantee all intended parties are included in the call.

The length of time it takes to update the affiliation tables depends on the number of sites, radios, and talkgroups in the system, but in general it should be less than twenty minutes from the time the first site transitions back to wide area trunking.

As with radios, console affiliations must also be sent to the controller within the zone. This happens within the fist few minutes after the switchover occurs.

For a given talkgroup to be monitored by the dispatch subsystem, at lease one console affiliation must be received for that talkgroup.

5.11.3.2 Switching Back to the Standby Controller (User Initiated)

Do not switch back to the standby controller until the Infrastructure database has been downloaded from the Zone Database Server (ZDS) or the system remains in local site trunking until the Infrastructure database has been downloaded. The download time varies by system configuration, but in general should take less than 10 minutes.

5.11.3.2.1 Infrastructure Database Download

There is no indication that the download has completed other than the controller state changing to enabled idle or enabled active.

The controller begins acknowledging the link requests from the sites once the database is downloaded. A link request contains information such as the site ID. The controller checks the site ID against the information in the database and requests the site's capabilities. The controller instructs the site to transition to wide area trunking if the capabilities are normal. The controller then requests the affiliation tables for radios and talkgroups. This operation is performed for every site in the system. The controller handles multiple sites simultaneously.