The process of setting up HA will vary slightly depending on whether this is an existing operating single to which a second unit is being added to form an HA pair, or a new pair of units are being deployed from scratch.
Starting from an existing single unit setup
Important: When setting up HA where there is an existing single configured PABX you should ensure that a backup of configuration and data from that PABX are taken before commencing setup.
Starting with a single unit which has been configured on one IP address as a non-HA unit, the following steps should be used to set up an HA pair:
On both units go to the High Availability screen and select the Configuration Menu. The only available option on an initially non-HA unit is password. Enter the same password on both units to allow the units to synchronise their config and press the Update button.
When the screen refreshes, on the initial primary unit select HA ON and enter the High Availability IP address and Unit-1 and Unit-2 IP Addresses.
Note: By default, the current unit IP address will be entered into the High Availability IP address field so that the new shared IP address is the same as the current unit’s single IP address. This configuration generally has the least impact on network configuration. If you wish to retain this configuration simply leave this address in place and enter a different IP address into the Unit-1 field which will change your unit IP address on reboot.
Press the Sync Configuration button to push this configuration to the second unit.
Shut-down the unit that has been added to the pair.
Reboot the pre-existing unit. Verify that it starts up with the same configuration as previously. If the IP address has changed, reboot handsets to pick up the new configuration then verify that calls work.
Open the web-page on the System/High Availability/Status screen.
Power up the secondary unit and wait for it to be recognised.
Important: If the restart order above is not strictly followed then the PABX configuration and data files (voicemails, faxes, call recordings etc) will be synced from the new empty unit to the existing PABX. This will result in loss of the configuration and all data on the existing PABX.
Starting with no configured units
The sequence of steps are less critical in this case although we would recommend broadly following the process above. The important sequence is ensuring that each unit is configured with its own unique primary IP address, both units are assigned the same HA password and then the HA configuration is synchronised from one unit to the other before rebooting both unit.
Important: In any HA configuration it is important to ensure that the network configuration: DNS names, firewall rules for SIP trunk access etc all point to the shared failover IP address rather than either of the unit IP addresses so that service resumes seamlessly should a unit fail.
Note: When setting up an HA pair of units from scratch, this should be the first operation after setting basic networking parameters on the individual units. All further configuration will then be simultaneously applied on both units.