User's Manual

RealPresence Collaboration Server (RMX) 1500/2000/4000 Administrator’s Guide
23-36 Polycom, Inc.
MLPP (Multi Level Precedence and Preemption)
In compliance with UC APL requirements, Quality of Service (QoS) can be more accurately
modified to suit local needs with the addition of Multi Level Precedence and Preemption
methods for call prioritizing and call handling.
QoS is important when transmitting high bandwidth audio and video information. QoS can
be measured and guaranteed in terms of:
•Latency
• Low packet throughput
• Average delay between packets
• Jitter (variation in delay)
• Transmission error rate
• Order of packet delivery
Precedence is the method by which a call is assigned a priority level. The RMX supports two
separately defined and configurable Domains, each having its own Precedence policy.
For a full description of Precedence see IETF RFC 2474.
One of the following Precedence Levels is assigned to all calls:
Conferences can have a mix of participants from different Precedence domains and network
domains.
Precedence is supported for both IPv4 and IPv6.
Preemption is the method whereby, when system resources are insufficient, lower priority
calls are terminated and their resources assigned to higher priority calls. Preemption is
typically a function of network components such as the Local Session Controller (LSC). To the
RMX, a preempted call appears as a disconnected call.
Table 23-8 Precedence Levels
Highest Priority
FLASH-OVERRIDE-OVERRIDE (Classified Networks only)
FLASH-OVERRIDE
FLASH
IMMEDIATE
PRIORITY
Lowest Priority
ROUTINE