DMA Operations Guide Introduction to the Polycom DMA System
2 Polycom, Inc.
Conference Manager
The Polycom DMA system’s Conference Manager facilitates multipoint video
conferencing. A multipoint video conference is one in which multiple
endpoints are connected, with all participants able to see and hear each other.
The endpoints connect to a media server (Multipoint Control Unit, or MCU),
which processes the audio and video from each and sends the conference
audio and video streams back to them.
Traditionally, such multipoint conferences had to be scheduled in advance,
reserving ports on a specific MCU, in order to ensure the availability of
resources. Conference Manager makes this unnecessary.
Conference Manager uses advanced routing policies to distribute voice and
video calls among multiple MCUs, creating a single virtual resource pool. This
greatly simplifies multipoint video conferencing resource management and
uses MCU resources more efficiently.
The Polycom DMA system integrates with your Microsoft® Active
Directory®, automating the task of provisioning users with virtual meeting
rooms (VMRs), which are available for use at any time for multipoint video
conferencing. Combined with its advanced resource management, this makes
reservationless (ad hoc) video conferencing on a large scale feasible and
efficient, reducing or eliminating the need for conference scheduling.
The Polycom DMA system’s ability to handle multiple MCUs as a single
resource pool makes multipoint conferencing services highly scalable. You can
add MCUs on the fly without impacting end users and without requiring re-
provisioning. The DMA system can span a conference across two or more
MCUs (called cascading), enabling the conference to contain more participants
than any single MCU can accommodate.
The Conference Manager continually monitors the resources used and
available on each MCU and intelligently distributes conferences among them.
If an MCU fails, loses its connection to the system, or is taken out of service,
the Polycom DMA system distributes new conferences to the remaining
MCUs. Every conference on the failed MCU is restarted on another MCU
(provided there is space available). The consequences for existing calls in those
conferences depend on whether they’re H.323 or SIP:
• H.323 participants are not automatically reconnected to the conference. In
order to rejoin the conference, dial-in participants simply need to redial
the same number they used for their initial dial-in. Dial-out participants
will need to be dialed out to again; the DMA system doesn’t automatically
redial out to them.
• SIP participants are automatically reconnected to the conference on the
new MCU. This includes both dial-in and dial-out SIP participants. No
new dial-out is needed because the DMA system maintains the SIP call leg
to the participant and only has to re-establish the SIP call leg from the
DMA system to the MCU.