Galaxy Expand - High Availability UCx Server Configuration

UCx High Availability Server Deployment

The Galaxy Expand is ideally suited for creating a High Availability solution through the use of redundant Server Cards. The chassis is always equipped with dual power supplies providing maximum protection against power outages, as the two power supplies can be connected to different 120VAC circuits. But the fact that the chassis can support multiple server cards means that a single chassis can be used to deploy the High Availability Redundant Configuration (HARC) software.  Another option would be to use two separate chassis with a server card in each one.

Galaxy Expand Hardware Requirements

Required cards

When deployed as a High Availability Redundant Configuration (HARC) UCx server, the configuration requires two identical Galaxy Expand Server Cards. The choice of which Server card is based upon the number of extensions required or the number of simultaneous calls required for the call server.  The capacities of the server cards is described in Galaxy Expand - Platform Hardware.

Optional Cards

In a HARC system, all connecting equipment must use IP communication between the UCx and itself.  For this reason, only the Telephony interface cards using the Ethernet backplane can be used in the chassis.  As noted in Galaxy Expand - Platform Hardware, these cards include the DSM16, PRI, and FXS16 cards.  If a single chassis is used, these can be configured in any of the nine remaining slots. An additional server card can also be installed, but the third server card would be used as a standalone InfinityOne server, which is described later in this document. Note that for an all IP based configuration with only IP telephones and SIP trunks, no telephony cards are required. 
For details on how to configure the optional Telephony Interface Cards, refer to the following:

  1. DSM16 Card Configuration (Ethernet Enabled)
  2. PRI Card Configuration (Ethernet Enabled)
  3. FXS16 Card Configuration (Ethernet Enabled)

Server Card Network Connection and Configuration

Slot assignment for Required Cards

When deploying the Galaxy Expand as a High Availability UCx server, you will be required to install one of the selected Galaxy Expand Server Cards in either slot 2a, 7a, or 11a as noted in Galaxy Expand - Platform Hardware. When the single slot 2930 Call Server card is used the corresponding "b" slot for that location should be covered with a blank card slot cover. The second server card should be installed in one of the two remain server cards slots. It is also possible to deploy the second server card in a second chassis, however this results in the ethernet cable connecting the two as a single point of failure, so E-MetroTel recommends deploying both server cards in the same chassis, even if a second chassis is required for additional telephony cards.

Recommended IP Addressing - 2930 Server Card

When using a Galaxy Expand 2930 Server Card, there is only a single "customer facing" ethernet interface.  As with all UCx software, the default value for the IP address of the ETH interface on the server card is  However, per the High Availability - Installation and Configuration, this address should be be changed so that the default UCx address can be used as the Cluster IP Address. In the example below Ethernet 0 in the UCx software on one of the two server cards has been configured as and should be connected to the customer LAN. All configuration of the 2930 Server Card parameters should be done in accordance with the UCx Network Parameters documentation.  The Ethernet 0 interface on the second server card should also be changed from the default value; in the example it is set to and should also be connected to the customer LAN. A third address will be configured per the High Availability - Installation and Configuration documentation, as is shown as

The Galaxy Expand chassis backplane ethernet network will be identified in the UCx software as Ethernet 2. The E-MetroTel recommended addressing for this interface is with a subnet mask of, which is the default setting for this interface.  The DHCP Server in the UCx software enabled by default and is configured to provide IP addresses for this subnet. This will allow any Ethernet based cards in the system to acquire an IP address and communicate to the server card in their own subnet. If the address range conflicts with your network addressing, following the instructions in the UCx DHCP Server documentation. 

Note that the second Galaxy Expand Server Card should not be added while any other cards are still in the process of aquiring an IP address from the first server card.  The DHCP Server on the second card shuold be immediately de-activated to avoid potential 


Recommended IP Addressing - i5 Server Card

The IP Addressing scheme identified above for the 2930 Server card should be used as the baseline configuration for High Availability configuration using the Galaxy Expand i5 Server Card.  However, the i5 Server Card has an additional Ethernet interface on the front panel.  This second ethernet connector should be configured on a distinct subnet, either assigned manually or via DHCP.  E-MetroTel suggest configuring the card as when in a standalone configuration, but since the first Ethernet interfaces on each card in a High Availability configuration are recommended as and it is recommended that the second interface on each card be set to and, respectively.


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