Polycom
®
RealPresence DMA
®
7000 System Overview
Polycom, Inc. 19
● 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 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 RealPresence 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.
Single-server Configuration
The Polycom RealPresence DMA system is also available in a single-server configuration. This
configuration offers all the advantages of the Polycom RealPresence DMA system except the redundancy
and fault tolerance at a lower price. It can be upgraded to a two-server cluster at any time.
This manual generally assumes a redundant two-server cluster. Where there are significant differences
between the two configurations, those are spelled out.
Superclustering
To provide geographic redundancy and better network traffic management, up to five geographically
distributed Polycom RealPresence DMA system clusters (two-server or single-server) can be integrated into
a supercluster. All five clusters can be Call Servers (function as gatekeeper, SIP proxy, SIP registrar, and
gateway). Up to three can be designated as Conference Managers (manage an MCU resource pool to host
conference rooms).
The superclustered Polycom RealPresence DMA systems can be centrally administered and share a
common data store. Each cluster maintains a local copy of the data store, and changes are replicated to all
the clusters. Most system configuration is supercluster-wide. The exceptions are cluster-specific or
server-specific items like network settings and time settings.