Polycom 3725-76302-001LI manual 284

DMA Operations Guide About Site Topology

Note

Site topology information provides a logical model representation of a network topology, not necessarily a fully accurate literal representation of a full network.

The Polycom DMA system uses site topology information for a variety of purposes, including cascading of conferences, bandwidth management, Session Border Controller selection, and cluster responsibility management in a supercluster. It can get it in one of two ways:

•If you have a Polycom RealPresence Resource Manager or CMA system, integrate the Polycom DMA system with it (see “Resource Management System Integration” on page 185) to automatically get its site topology information.

Note

Integration with a Polycom RealPresence Resource Manager or CMA system is not supported in Maximum security mode.

•If you don’t have a Polycom RealPresence Resource Manager or CMA system, enter site topology information about your network directly into the Polycom DMA system’s site topology pages.

If your Polycom DMA system is superclustered (see “About Superclustering” on page 227), site topology data only needs to be created (or obtained from a Polycom RealPresence Resource Manager or CMA system) on one cluster of the supercluster. It’s replicated across the supercluster.

For a conference with cascading enabled, the Polycom DMA system uses the site topology information to route calls to the nearest eligible MCU (based on pools and pool orders) that has available capacity and to create the cascade links between MCUs.

When determining which MCU is “nearest” to a caller and which path is best for a cascade link, the system takes into account the bandwidth availability and bit-rate limitations of alternative paths.

Note

Cascading always uses a hub-and-spoke configuration so that each cascaded MCU is only one link away from the “hub” MCU, which hosts the conference. The conference is hosted on the same MCU that would have been chosen in the absence of cascading, using the pool order applicable to the conference. See “MCU Pool Orders” on page 156.

The cascade links between RMX MCUs must use H.323 signaling. For conferences with cascading enabled, the Polycom DMA system selects only MCUs that have H.323 signaling enabled.

This cascade link requirement doesn’t affect endpoints, which may dial in using SIP (assuming the MCUs and the Polycom DMA system are also configured for SIP signaling).

284 Polycom, Inc.