Redundancy / High Availability


World-class redundancy is built into every MX system, from power to LAN connectivity to PSTN services. This high degree of redundancy ensures that regardless of the failure, the MX system will continue to operate without loss of function for the enterprise and users.

RAID-1 Design
Each MX system is shipped with a commercial quality hard disc drive. This HDD stores the system’s operating software, voice mail messages and call recording sessions, user and automated attendant prompts and greetings, and customer-defined system configuration files. For those clients wishing to protect their investment against disc failure, the optional RAID-1 HDD and software may be equipped. Unlike other systems that merely provide back-up of system configuration programming, all operations and files associated with the deployed MX is protected. Should one hard drive fail the system will continue to operate with the remaining hard drive without any service interruption or data loss.

Redundant Power Inputs
The MX system is normally powered via connection to a suitable 110-240 VAC power outlet. In the event of commercial power failure, the system may be protected against outage by deploying the BPS12 battery power supply. This compact but powerful unit is capable of powering not only the MX system itself, but also any peripheral devices that may be installed, such as data switches, music on hold sources, and paging equipment. Weighing under 70 pounds (35 Kg), the BPS12 is lightweight enough for 19′ rack mounting, and provides vented convection cooling to minimize damage that is possible in over-heated equipment closets or crowded server rooms.

Dual 10/100Base Ethernet Ports
Two Ethernet ports are provided by each MX system. These two ports can be used to protect your phone communications against IP network failures. In this bridged configuration, the MX system remains fully operational should there be a failure to the original LAN connection provided to the MX.


On-board FXS Ports
The MX system provides two on-board FXS ports for the connection of analog single-line devices, such as fax machines, elevator emergency phones or credit card readers. The built-in availability of these FXS ports reduces a client’s need to purchase a separate FXS-8 module to deploy such equipment, thereby reducing the cost and loss of system “real estate” required by the FXS-8 module.

But in addition to providing a cost effective means of connecting analog station devices, these FXS ports serve at power failure transfer ports for analog trunks provided by the PSTN carrier. In the event of a power outage, the first two analog trunks are automatically switched to the built-in FXS ports of the system. This ensures that communications to the outside world is not lost during a power outage.

Field Replaceable Fans
The potential for failure in any communications platform is normally related to those components with moving parts. This is true of the MX system as well. The fan assembly of the MX platform is built with two fan units installed on the same board. The board is mounted onto a removable tray assembly. In the even that one of the fans fails, the other fan is sufficient to cool the system. In the event of a fan failure or noise develops due to fan wear, the fan assembly is easily replaced by field personnel without taking the MX system offline.


An MXcluster configuration is used to extend a single MX system beyond its capacity of 250 users. Up to 3 additional MX systems may be connected to a main MX system. Each added MX system in an MXcluster doubles the base capacity.

Clustering may also be used to provide redundancy of any MX in the cluster. Available deployments include 1+1, 2+1 or 4+1 configurations. In each case, the “+1” indicates a separate non-clustered MX system that is available as a survivable replacement in the event of a failure of any system in the MXcluster. The single redundant system is updated continually with the programming, messaging and user profiles in each of the other MX systems in the MXcluster. If a failure occurs in any of the clustered systems, the stand-by MX system takes the place of the failed system. A short reboot cycle of 3-5 minutes brings the redundant system online, in the virtual place of the failed system. No intervention on the part of the system administrator or service personnel is required for the switch-over to the redundant system to occur.

XRS12 Switching Module
To further support redundant configurations, Zultys provides the optional XRS12, a relay switch that mounts in a 19″ rack along with the enterprise’s MX system. The XRS12 occupies only 1 RU of rack space. The XRS12 provides the switching mechanism to connect the PSTN circuits of each MX to the redundant standby MX system. In this configuration, if an individual MX fails, the XRS12 automatically switches the PSTN trunk connections from the failed MX250 to the standby MX. Using the XRS12, an MXcluster retains full connectivity to the PSTN after a switch-over without intervention from the administrator.


Disaster Recovery Configurations
In the event of a complete system failure, survivability may be provided through the deployment of an MX25 IP Gateway. In this configuration, the MX25 operates as a back-up system to which users may register to ensure that at least a minimal number of users can remain online and operational.

Additionally, the operating software of the MX system permits ICC agents and Group members to log into foreign systems. By doing so, if the members’ “home” system is unavailable for any reason, calls to Groups and ICC queues will continue to be handled. If it is safe to do so, the users can remain at their normal workspace and simply bind their IP phones to a different MX system within the MXgroup.

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