Polycom 7000 manual Bandwidth Management

Site Topology

The RealPresence DMA system uses site topology information for a variety of purposes, including cascade for bandwidth 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 system, integrate the Polycom RealPresence DMA system with it (see RealPresence Resource Manager Integration) to automatically get its site topology information.

Note: Integration not supported in maximum security mode

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

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

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

For a conference with cascading for bandwidth enabled, the RealPresence 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: MCU Cascading considerations

Cascading for bandwidth 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.

The cascade links between MCUs must use H.323 signaling. For conferences with cascading enabled, the Polycom RealPresence 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 RealPresence DMA system are also configured for SIP signaling).

Bandwidth Management

Once you model a site topology to represent your physical network, you can use it to manage bandwidth between your sites, preventing conference traffic from saturating the network.

Before the RealPresence DMA system routes a call, it considers the source and destination IP addresses in the site topology and determines a media path from the source subnet to the destination subnet, taking into account the existing calls and bandwidth restrictions along that path. If sites or site links have bandwidth restrictions, the system reduces the call rate of the call at the time of call setup so that it meets those restrictions, if possible. If the media path is already saturated with other conference traffic, the RealPresence DMA system rejects the call attempt.

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