Conferencing Modes Overview
Polycom®, Inc. 23
MCU Resource Capacities for Mixed CP and SVC Conferences
In a mixed CP and SVC conference, video resources are allocated according to the MCU type and the
translation pools (AVC to SVC and SVC to AVC) used to convert video streams. Translation pools are
dynamically allocated, when the conference becomes a mixed CP and SVC conference; resources are not
released when the conference stops being a mixed CP and SVC conference. The translation pools send
one SVC to AVC stream with a resolution of 360p, two AVC to SVC streams with a resolution of 360p and
180p for AVC HD endpoints, and one video stream with a resolution of 180p for AVC SD endpoints. When
a video stream with a resolution of 360p is not available, a video stream with a resolution of 180p is sent
instead.
Translations between different endpoints can be done without using the highest resolution, thus saving
translation resources. CP video layouts in mixed CP and SVC conferences support the standard resolutions
as in normal CP conferences.
Taking these factors into consideration and the type of MCU deployed in the environment, the resource
capacities for a mixed CP and SVC conference can vary.
For information on resource capacity allocations for the RealPresence Collaboration Server see Resource
Capacities for Full Capacity Collaboration Server per Resolution in Mixed CP and SVC Conferencing.
In a mixed CP and SVC conference, video resources are used according to the amount of both AVC and
SVC participants in the conference and according to the actual type of the conference - mixed CP and SVC
conferences or CP only conferences. The ratio of resources in a mixed conference is one AVC HD (720p30)
video resource to three SVC video resources, meaning for each AVC HD video resource, three SVC video
resources can be allocated.
In this resource capacity allocations example, the mixed CP and SVC conference can allocate a
combination of AVC and SVC ports depending on the endpoints that are defined in the actual conference.
For example, a conference can be defined as a mixed CP and SVC conference but will only allocate
resources as a mixed conference when both AVC and SVC endpoints join the conference. When there are
only one resource type of endpoints participating in the conference, such as AVC or SVC, the resource
allocations are assigned according to the type of endpoint with the system flag
MIX_AVC_SVC_DYNAMIC_ALLOCATION set to TRUE. For instance, a mixed CP and SVC conference
with HD endpoints assigned, can have 60 or 120 ports allocated depending on the server configuration.
When an SVC endpoint joins the conference, the conference becomes an actual mixed conference and the
resource allocations are divided between the AVC and SVC endpoints. The Resource Report will reflect this
by showing an increase in the resource usage.
System Resources are now reported in terms of HD720p30 CP ports. One HD video port equals 3
CIF video ports.