Enabling Precedence - Polycom RealPresence 4000 Administrator's Manual

RealPresence Collaboration Server (RMX) 1500/2000/4000 Administrator's Guide
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.

Enabling Precedence

Precedence is disabled by default. It is enabled by using the Setup > Precedence Settings
menu to display the Precedence Settings dialog box. Precedence is enabled by selecting the Use
Precedence check box.
See "Configuring and Modifying Precedence Domains and DSCP Values" on page 23-42.
When Precedence is enabled, all other QoS system settings are overridden by the parameters
sent in the SIP Message. For more information about QoS, see the RealPresence® Collaboration
Server (RMX) 1500/2000/4000 Administrator's Guide, "Network Services" on page 1-1.
SIP Message
A SIP Message is a request or a response between network entities that communicate using
the SIP protocol. The SIP Message header contains Precedence and Resource Priority (r-value)
information and an optional Require tag for each call.
For a full description of SIP Messages see IETF RFC 3261.
For a full description of Resource Priority (DSCP) see IETF RFC 2474.
For a full description of SIP r-priority see IETF RFC 4412.
Dial-in calls
If the Use Precedence check box in Precedence Settings is selected:
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