The majority of VOCAL servers transmit regular pulses called
, which allow the other hosts on the network to determine whether any of the servers are down. The Heartbeat server manages the heartbeat flow. The following servers simply send heartbeats:
Call Detail Record server
Conference Bridge Marshal server
Gateway Marshal server
Internet Marshal server
User Agent Marshal server
Voice Mail User Agents
The following servers perform more complex tasks:
Heartbeat server listens for heartbeats from all other components except for the Voice Mail User Agents.
Provisioning server sends heartbeats and listens for heartbeats from the other Provisioning server (if a redundant server exists).
Redirect server sends heartbeats and listens for heartbeats from the other Redirect server (if a redundant server exists), as well as from all Feature servers and Marshal servers.
Voice Mail Feature server sends heartbeats and listens for heartbeats from only the Voice Mail User Agents.
The following servers neither send nor listen for heartbeats:
Network Manager server
Voice Mail server
The Heartbeat server is used by the Network Manager to update the GUI table of servers and server states. If your system does not include a Network Manager, the Heartbeat server is not required. For more information about network management, see Chapter 17.
Table 6-20 shows the provisioning tasks that can be performed with the Heartbeat servers.
Table 6-20. Heartbeat server ...