Introduction to the Polycom DMA System

Polycom® DMA7000 System Overview

The Polycom DMA System’s Three Configurations

Two-server Cluster Configuration

The Polycom DMA system is designed to be deployed as a pair of co-located redundant servers that share the same virtual IP address(es). The two-server cluster configuration of the Polycom DMA system has no single point of failure within the system that could cause the service to become unavailable.

The two servers communicate over the private network connecting them. To determine which one should host the public virtual IP address, each server uses three criteria:

Ability to ping its own public physical address

Ability to ping the other server’s public physical address

Ability to ping the default gateway

In the event of a tie, the server already hosting the public virtual address wins.

Failover to the backup server takes about five seconds in the event of a graceful shutdown and about twenty seconds in the event of a power loss or other failure. In the event of a single server (node) failure, two things happen:

All calls that are being routed through the failed server are terminated (including SIP calls, VMR calls, and routed mode H.323 calls). These users simply need to redial the same number, and they’re placed back into conference or reconnected to the point-to-point call they were in. The standby server takes over the virtual signaling address, so existing registrations and new calls are unaffected.

Direct mode H.323 point-to-point calls are not dropped, but the bandwidth management system loses track of them. This could result in overuse of the available network bandwidth.

If the failed server is the active web host for the system management interface, the active user interface sessions end, the web host address automatically migrates to the remaining server, and it becomes the active web host. Administrative users can then log back into the system at the same URL. The system can always be administered via the same address, regardless of which server is the web host.

The internal databases within each Polycom DMA system server are fully replicated to the other server in the cluster. If a catastrophic failure of one of the database engines occurs, the system automatically switches itself over to use the database on the other server.

Polycom, Inc.

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Polycom 3725-76302-001LI manual Polycom DMA System’s Three Configurations, Two-server Cluster Configuration